JP4856012B2 - Radio communication system, radio communication station apparatus, and radio communication method - Google Patents

Description

The present invention relates to a radio communication system, a wireless communication station apparatus location Contact and wireless communication method, in particular, a plurality of the radio communication station apparatus cooperation in all the frequency bands of the utilization object, there are radio waves of other radio communication systems Detection based on the signal strength measurement results of each frequency band, enabling communication using a frequency band in which radio waves of other wireless communication systems do not exist, and further measuring the signal strength based on the results, a transmission method and a transmission power amount can select wireless communication system used for communication, a radio communication station apparatus location Contact and wireless communication method.

  In general, in radio communication, there is a limit to frequency resources, and thus technology for effectively using frequencies is essential. In order to effectively use this frequency, a technique for improving the transmission rate per 1 Hz, such as multi-level modulation and error correction code, or a cellular system using a cell-based frequency repetitive utilization method, by one cell repetitive Conventionally, various studies such as a CDMA communication system and an interference canceller have been performed.

  On the other hand, in recent years, the concept of “cognitive radio” in which wireless communication is performed using an empty frequency band in which no radio wave exists has been highlighted. The cognitive radio system is a mechanism in which a radio communication station device itself searches for a currently available frequency band in the vicinity of the radio communication station device, and uses it for communication among all frequency bands to be used. If there is a frequency band that is not currently used in each wireless communication system, depending on the region or region, the frequency band can be used for wireless communication in the wireless communication station device. Can be expected to be used effectively.

  The wireless communication station apparatus detects a frequency band in which no radio wave exists by using the wireless communication station apparatus itself or a wireless terminal apparatus existing in a service area covered by the wireless communication station apparatus, and performs communication using the frequency band. Will do. Here, as a method of detecting a frequency band in which no radio wave exists, there is a method of detecting the signal intensity (signal level) of each frequency band of candidates to be used for communication among all frequency bands to be used.

  For example, all frequency bands to be used are divided into bands having a certain band, and each band is converted to a baseband signal using an RF circuit such as an orthogonal demodulator / synthesizer that can operate over a wide band. There is a method of measuring a signal intensity (signal level), that is, an electric energy, and searching for a band whose signal intensity is lower than a predetermined threshold. Alternatively, using a bandpass filter that can variably control the center frequency, the center frequency is sequentially changed to measure the signal level in each band, and a band with a low signal strength (signal level) is searched. The method of thinking is also conceivable.

  A band whose signal strength (signal level) is lower than a threshold is considered to be a free frequency band because it is judged that the influence of interference on other radio communication systems or interference from other radio communication systems is small. This frequency band may be used for the current communication.

For example, Japanese Patent Laid-Open No. 5-145460 “Signal Detection Device” of Patent Document 1 discloses a wireless communication station apparatus that enables a plurality of wireless communication station apparatuses to repeatedly use a frequency band of the same channel. Each measures the received signal strength of the signal for each channel, and detects a channel whose measured signal strength is equal to or less than a predetermined threshold as a free channel, that is, a free frequency. In order to reduce the misjudgment probability, the arrival probability of the signal wave for each channel is measured, and the threshold used for determining the free frequency band according to the thermal noise average level and the allowable interference average level set from the outside A method of setting the level variably has been proposed. Here, the technique of Patent Document 1 searches for a free channel, that is, a free frequency, in each wireless communication station device alone without performing a cooperative operation between the wireless communication station devices constituting the wireless communication system. It is a technique.
JP-A-5-145460

  As described above, each of the conventional techniques such as Patent Document 1 is not available in each wireless communication station device alone without any cooperation between the wireless communication station devices constituting the wireless communication system. A technique for searching for a frequency is employed. For this reason, when the reception level of a radio wave from another wireless communication system is temporarily weakened due to shielding or fading by an obstacle, an erroneous detection that considers that frequency band as an empty frequency band occurs. There is a problem.

  In addition, depending on the detection accuracy of a device that detects a vacant frequency such as a bandpass filter, a large error occurs in the vacant frequency to be detected, and there is a risk of causing false detection.

  As described above, when communication is performed using an erroneously detected vacant frequency, there is a problem in that radio wave interference occurs and the communication quality of a wireless communication system that interferes with each other significantly decreases.

The present invention has been made in view of such problems, and a radio communication system and a radio communication station that can more reliably determine whether or not radio waves of other radio communication systems exist around the radio communication station apparatus. to provide a equipment Contact and wireless communication method, it is an object.

  In order to solve the problems as described above, in the present invention, the signal strength of each frequency band is set for all the frequency bands of the supplement used for communication in cooperation between the radio communication station apparatuses constituting the radio communication system. It has the characteristic in adopting the structure which improves the detection accuracy of a vacant frequency by measuring and determining the presence or absence of the electromagnetic wave of another radio | wireless communications system. That is, in each wireless communication station device, by measuring the signal strength of each frequency band and determining an available frequency, and exchanging the measurement results and determination results between the wireless communication station devices, In addition, a configuration is adopted in which a search is made for a free frequency band in the vicinity of the own wireless communication station apparatus using measurement results and determination results in other wireless communication station apparatuses.

  More specifically, the present invention comprises the following technical means.

The first technical means is a radio communication system comprising a plurality of radio communication station apparatuses that communicate with one or more radio terminal apparatuses existing in a service area using radio signals in a frequency band assigned at the start of communication. The radio communication station apparatus comprises: a signal strength measuring unit that measures signal intensity of a radio signal existing around the radio communication station apparatus for all frequency bands to be used; and a frequency of a radio signal used for communication with the radio terminal apparatus Use frequency determining means for determining a band, and communication means for transmitting and receiving information to and from each other between a plurality of wireless communication station devices, and the measurement result of the signal strength of the radio signal measured by the signal strength measuring means, The communication means transmits the signal strength measurement result of the radio signal transmitted from the other radio communication station apparatus to the other radio communication station apparatus. Received by the communication means, and transmitted from the other radio communication station apparatus received by the communication means and the measurement result of the signal intensity measured by the signal intensity measurement means of the own radio communication station apparatus by the use frequency determining means Based on the measurement result of the signal strength that has been transmitted, it is determined whether or not there is a free frequency in the vicinity of the own wireless communication station device, and the wireless result is determined based on the determination result determined as a free frequency. A radio communication system for determining a frequency band of a radio signal used for communication with a terminal device , wherein the use frequency determining means includes the measurement result of the signal strength measured by the own radio communication station device and another radio communication station. The measurement result of the signal strength of the other radio communication station apparatus transmitted from the apparatus is used for all frequency bands to be used for each frequency band. A weight correction unit that performs weight correction using a correction value; a measurement result of the signal strength of the own wireless communication station device that has been weight-corrected by the weight correction unit; and a wireless communication station device that is transmitted from another wireless communication station device A determination means for comparing the measurement result of the signal strength with a predetermined threshold value for determining a free frequency, and outputting a determination result of the signal strength indicating whether the frequency is a free frequency; A calculation means for performing a calculation for determining whether or not the signal strength of the station apparatus is a free frequency around the own radio communication station apparatus, and is set in advance in the weight correction means The weight correction value is the distance between the radio communication station devices, the degree of correlation with the signal strength of the received signal between the radio communication station devices, the installation location of the radio communication station device, the radio communication station device It is determined according to any one or more of the communication time zone of the wireless communication station apparatus and the interference occurrence history information in the past communication of the wireless communication station apparatus .

The second technical means is a wireless communication system comprising a plurality of wireless communication station devices that communicate with one or more wireless terminal devices existing in a service area using wireless signals in a frequency band assigned at the start of communication. The wireless terminal device includes a signal strength measuring unit that measures the signal strength of a wireless signal existing around the wireless terminal device for all frequency bands to be used as a terminal measurement result of the signal strength, and a service in which the wireless terminal device exists. And at least terminal-side transmission / reception means for transmitting / receiving information to / from the wireless communication station apparatus in the area, wherein the wireless communication station apparatus and the one or more wireless terminal apparatuses existing in a service area of the wireless communication station apparatus A station apparatus side transmitting / receiving means for transmitting and receiving and a use frequency determination for determining a frequency band of a radio signal used for communication with the wireless terminal apparatus Means and at least communication means for transmitting / receiving information to / from each other between the plurality of radio communication station apparatuses, wherein the radio terminal apparatus obtains the terminal measurement result of the signal strength measured by the signal strength measurement means as the terminal Is transmitted to the radio communication station apparatus by the side transmission / reception means, and the radio communication station apparatus transmits the signal strength transmitted from one or more of the radio terminal apparatuses existing in the service area of the radio communication station apparatus. The terminal measurement result is received by the station apparatus side transmission / reception means, and transmitted to the other wireless communication station apparatus by the communication means, while the terminal measurement result of the signal strength transmitted from the other wireless communication station apparatus is received. , Terminal measurement of the signal strength received by the communication means, and received by the station apparatus side transmitting / receiving means of the own radio communication station apparatus by the use frequency determining means Based on the result and the terminal measurement result of the signal strength transmitted from the other radio communication station apparatus received by the communication means, whether or not there is a radio frequency in which no radio signal exists in the vicinity of the own radio communication station apparatus A wireless communication system for determining a frequency band of a wireless signal used for communication with the wireless terminal device based on a determination result determined as an empty frequency , wherein the used frequency determining means The terminal measurement result of the signal strength of the station device and the terminal measurement result of the signal strength of the other radio communication station device are weight-corrected by a preset weight correction value for each frequency band for all frequency bands to be used. Weight correction means to be applied, and the terminal measurement result of the signal strength of the own radio communication station apparatus and the signal of the other radio communication station apparatus that have been weight-corrected by the weight correction means A determination means for comparing a terminal measurement result of strength with a predetermined threshold for determining a free frequency, and outputting a determination result of signal strength indicating whether or not it is a free frequency, and the own wireless communication station device and another wireless communication station; A calculation means for performing a calculation for determining whether or not the signal strength determination result of the apparatus is an empty frequency around the radio communication station apparatus; and the weight set in advance in the weight correction means The correction value is the distance between the wireless communication station devices, the degree of correlation with the signal strength of the received signal between the wireless communication station devices, the installation location of the wireless communication station device, the communication time zone of the wireless communication station device, the past of the wireless communication station device It is determined according to any one or more of interference occurrence history information in the communication .

A third technical means is a wireless communication system comprising a plurality of wireless communication station devices that perform communication using a wireless signal in a frequency band assigned at the start of communication with one or more wireless terminal devices existing in a service area. The wireless terminal device includes a signal strength measuring unit that measures the signal strength of a wireless signal existing around the wireless terminal device for all frequency bands to be used as a terminal measurement result of the signal strength, and a service in which the wireless terminal device exists. And at least terminal-side transmission / reception means for transmitting / receiving information to / from the wireless communication station apparatus in the area, wherein the wireless terminal apparatus transmits / receives a terminal measurement result of the signal strength measured by the signal strength measurement means to the terminal-side transmission / reception Means for transmitting to the radio communication station apparatus, and the radio communication station apparatus is present in a service area of the radio communication station apparatus. Between a plurality of radio terminal apparatuses, a station apparatus side transmitting / receiving means for transmitting / receiving information to / from the plurality of radio terminal apparatuses, a use frequency determining means for determining a frequency band of a radio signal used for communication with the radio terminal apparatus, and a plurality of radio communication station apparatuses in a communication means for transmitting and receiving information with each other, at least comprising, furthermore, before Symbol used frequency determination means, received by the station side transmitting and receiving means, one or a plurality of existing in the service area of the wireless communication station By calculating and averaging the terminal measurement result of the signal strength transmitted from the wireless terminal device for each frequency band for all frequency bands to be used, the measurement result of the signal strength in the own wireless communication station device is obtained. the average calculation means for calculating an average value applicable, at least with the radio communication station apparatus, the addition was calculated by the average calculation unit Rights The value, the pre-Symbol communication means, while transmitting the other radio communication stations, the average value that has been transmitted from another wireless communication station receives the previous SL communication means, wherein use frequency determination The result of further averaging the addition average values of the own radio communication station device and the other radio communication station device by means is compared with a predetermined threshold value for determining a free frequency , and wirelessly transmitted around the own radio communication station device. It is a wireless communication system that determines whether or not a signal is a free frequency, and determines a frequency band of a wireless signal to be used for communication with the wireless terminal device according to a determination result determined as a free frequency, The use frequency determining means is the addition average value of the own radio communication station apparatus calculated by the average calculation means and the addition average of the other radio communication station apparatus received by the communication means. The value of the weight correction unit that performs weight correction with a weight correction value set in advance for each frequency band for all frequency bands to be used, and the weight correction unit that is weight corrected by the weight correction unit. A result obtained by further adding the addition average value and the addition average value of the other radio communication station device is compared with a predetermined threshold for vacant frequency determination, and a signal strength determination result indicating whether or not the frequency is vacant is output. A determination means, a calculation means for performing a calculation to determine whether or not the signal strength determination result of the own radio communication station apparatus and other radio communication station apparatus is an empty frequency around the own radio communication station apparatus; The weight correction value preset in the weight correction means is a distance between radio communication station devices and a signal strength of a received signal between radio communication station devices. Seki degree, location of the wireless communication station, a communication time band of the wireless communication station, and wherein the interference generated history information in the past communications are determined according to any one or more of the wireless communication station To do.

In a wireless communication station apparatus that performs communication using a radio signal in a frequency band assigned at the start of communication with one or a plurality of wireless terminal apparatuses existing in the service area, the fourth technical means includes all the frequency bands to be used. A signal strength measuring means for measuring the signal strength of a radio signal existing around a radio communication station apparatus; a use frequency determining means for determining a frequency band of a radio signal used for communication with the radio terminal apparatus; and a plurality of radio communications At least communication means for transmitting and receiving information between the station apparatuses, and transmitting the measurement result of the signal strength of the radio signal measured by the signal intensity measurement means to another radio communication station apparatus by the communication means On the other hand, a signal strength measurement result of a radio signal transmitted from another radio communication station apparatus is received by the communication means, and is used by the use frequency determining means. Then, based on the measurement result of the signal strength measured by the signal strength measurement unit of the own radio communication station device and the measurement result of the signal strength transmitted from the other radio communication station device received by the communication unit. The frequency of the radio signal used for communication with the wireless terminal device is determined based on the determination result of determining whether the frequency is an empty frequency in the vicinity of the own radio communication station device. A wireless communication station apparatus that determines a band , wherein the use frequency determination means includes a measurement result of the signal strength measured by the own wireless communication station apparatus and another wireless communication station apparatus transmitted from the other wireless communication station apparatus. A weight correction unit that performs weight correction on a measurement result of the signal intensity for all frequency bands to be used for each frequency band using a weight correction value set in advance; and The signal strength measurement result of the own radio communication station apparatus and the signal strength measurement result of the other radio communication station apparatus transmitted from the other radio communication station apparatus, which have been weight-corrected by the corrective means, are preliminarily used for free frequency determination A determination means for outputting a signal strength determination result indicating whether or not the frequency is a free frequency compared to a predetermined threshold; and the signal strength determination results of the own wireless communication station device and the other wireless communication station device; A calculation means for performing a calculation for determining whether or not there is a free frequency around the radio communication station apparatus; and the weight correction value preset in the weight correction means is a distance between radio communication station apparatuses, a radio The degree of correlation between the signal strengths of the received signals between the communication station devices, the location of the wireless communication station device, the communication time zone of the wireless communication station device, and the occurrence of interference in the past communication of the wireless communication station device It is determined according to any one or more of history information .

According to a fifth technical means, in a wireless communication station apparatus that communicates with one or a plurality of wireless terminal apparatuses existing in the service area using a wireless signal in a frequency band assigned at the start of communication, the service area of the wireless communication station apparatus Station apparatus side transmitting / receiving means for transmitting / receiving information to / from one or more of the wireless terminal apparatuses existing in the network, a use frequency determining means for determining a frequency band of a radio signal used for communication with the wireless terminal apparatus, and a plurality of wireless terminals A communication means for transmitting / receiving information to / from each other between the communication station apparatuses, and from one or a plurality of the wireless terminal apparatuses existing in the service area of the wireless communication station apparatus, When the signal strength terminal measurement result is transmitted, it is received by the station apparatus side transmitting / receiving means, and is transmitted to another wireless communication station apparatus by the communication means. On the other hand, a terminal measurement result of the signal strength transmitted from another radio communication station apparatus is received by the communication means, and the station apparatus side transmission / reception means of the own radio communication station apparatus is received by the use frequency determining means Based on the terminal measurement result of the signal strength received by the communication means and the terminal measurement result of the signal strength transmitted from the other radio communication station device received by the communication means. Is a wireless communication station apparatus that determines whether or not a free frequency does not exist, and determines a frequency band of a wireless signal used for communication with the wireless terminal device according to a determination result determined as a free frequency , The use frequency determining means is configured to use a terminal measurement result of the signal strength of the own radio communication station device and a terminal measurement result of the signal strength of another radio communication station device as a whole circumference of a usage target. For several bands, for each frequency band, a weight correction unit that performs weight correction using a preset weight correction value, a terminal measurement result of the signal strength of the own wireless communication station device that has been subjected to weight correction by the weight correction unit, and A determination means for comparing a terminal measurement result of the signal strength of another wireless communication station device with a predetermined threshold for determining a free frequency, and outputting a determination result of the signal strength indicating whether or not it is a free frequency; Computation means for performing an operation for determining whether or not the signal strength determination result of the communication station apparatus and the other radio communication station apparatus is an empty frequency around the own radio communication station apparatus, and comprising at least the weight The weight correction value set in advance in the correction means includes the distance between the wireless communication station devices, the degree of correlation with the signal strength of the received signal between the wireless communication station devices, the wireless communication It is determined according to one or more of the installation location of the communication station device, the communication time zone of the wireless communication station device, and interference occurrence history information in past communication of the wireless communication station device .

According to a sixth technical means, in a wireless communication station apparatus that communicates with one or a plurality of wireless terminal apparatuses existing in the service area using wireless signals in a frequency band assigned at the start of communication, the service area of the wireless communication station apparatus Station apparatus side transmitting / receiving means for transmitting / receiving information to / from one or more of the wireless terminal apparatuses existing in the network, a use frequency determining means for determining a frequency band of a radio signal used for communication with the wireless terminal apparatus, and a plurality of wireless terminals At least communication means for transmitting / receiving information to / from each other between the communication station apparatuses, and the use frequency determining means is present in the service area of the wireless communication station apparatus received by the station apparatus side transmitting / receiving means. The terminal measurement result of the signal strength transmitted from the plurality of wireless terminal devices is obtained for each frequency band for all frequency bands to be used. By averaging, the average calculation means for calculating an average value corresponding to the measurement result of the signal strength in the radio communication station, at least provided with, the average value calculated by the average calculating means, wherein the communication unit, while transmitting the other radio communication stations, the average value that has been transmitted from another wireless communication station receives the previous SL communication means, by the use frequency determining means, the radio The result of further averaging the above-mentioned average value of the communication station device and the other wireless communication station device is compared with a predetermined threshold value for determining a free frequency, and there is a radio signal in the vicinity of the own wireless communication station device. The frequency band of the radio signal used for communication with the wireless terminal device is determined based on the result of the determination that the frequency is not available. In the wireless communication station apparatus, the use frequency determination means calculates the addition average value of the own wireless communication station apparatus calculated by the average calculation means and the addition average value of the other wireless communication station apparatus received by the communication means. , For all frequency bands to be used, for each frequency band, weight correction means for performing weight correction with a weight correction value set in advance, and the addition average of the own radio communication station apparatus weight-corrected by the weight correction means A determination means for comparing a result obtained by further adding the value and the addition average value of the other radio communication station device with a predetermined threshold value for determining a free frequency, and outputting a determination result of a signal strength indicating whether the frequency is a free frequency And, based on the signal strength determination results of the own radio communication station apparatus and the other radio communication station apparatus, determine whether the frequency is an empty frequency around the own radio communication station apparatus Calculating means for performing an operation for performing the calculation, wherein the weight correction value preset in the weight correction means is a correlation between a distance between radio communication station apparatuses and a signal strength of a received signal between radio communication station apparatuses It is determined according to one or more of the degree, the installation location of the wireless communication station device, the communication time zone of the wireless communication station device, and the interference occurrence history information in the past communication of the wireless communication station device. .

Seventh technical means is the radio communication station apparatus according to any one of the fourth to sixth technical means, wherein the signal of the own radio communication station apparatus is used as weight correction by the weight correction value in the weight correction means. Measurement result of strength and measurement result of signal strength of other radio communication station device transmitted from other radio communication station device, or terminal measurement result of signal strength of own radio communication station device and the above-mentioned of other radio communication station device The weight determined according to the distance between the radio communication station apparatuses, for either the terminal measurement result of the signal strength or the addition average value of the own radio communication station apparatus and the addition average value of the other radio communication station apparatus Either multiplying by a coefficient or adding or subtracting the amount of propagation loss determined according to the distance between the radio communication station apparatuses is performed.

Eighth technical means relates to another radio communication station apparatus that is within the range of a predetermined distance threshold from the radio communication station apparatus in the radio communication station apparatus described in the seventh technical means. As the weight correction by the weight correction value in the correction means, the signal strength measurement result of the other radio communication station apparatus transmitted from the other radio communication station apparatus or the signal strength terminal of the other radio communication station apparatus Either the measurement result or the addition average value of the other radio communication station apparatus is multiplied by a weighting factor of 0, or a propagation loss amount of a predetermined value is added. It is characterized by performing.

Ninth technical means relates to another wireless communication station apparatus in the wireless communication station apparatus described in the seventh technical means, wherein the weight is within a predetermined distance threshold range determined in advance from the own wireless communication station apparatus. As the weight correction by the weight correction value in the correction means, the signal strength measurement result of the other radio communication station apparatus transmitted from the other radio communication station apparatus or the signal strength terminal of the other radio communication station apparatus Either the measurement result or the addition average value of the other radio communication station apparatus is multiplied by a weighting factor proportional to the distance between the own radio communication station apparatus and the other radio communication station apparatus, Alternatively, either one of subtracting the amount of propagation loss that is inversely proportional to the distance between the own radio communication station apparatus and the other radio communication station apparatus is performed.

A tenth technical means relates to another radio communication station apparatus existing in a range exceeding a predetermined distance threshold from the own radio communication station apparatus in the radio communication station apparatus described in the seventh technical means, As the weight correction by the weight correction value in the weight correction means, the measurement result of the signal strength of the other radio communication station device transmitted from the other radio communication station device, or the signal strength of the other radio communication station device Is multiplied by a weighting factor that is inversely proportional to the distance between the own radio communication station apparatus and the other radio communication station apparatus. Or a propagation loss amount having a value proportional to the distance between the own radio communication station apparatus and the other radio communication station apparatus is added.

An eleventh technical means is the radio communication station apparatus according to any one of the fourth to tenth technical means, wherein the calculation means uses the own radio communication station apparatus for the determination result output by the determination means , and All of the measurement results of the signal strength of the other radio communication station apparatus, or all of the terminal measurement results of the signal strength of the own radio communication station apparatus and the other radio communication station apparatus, or the own radio communication station apparatus and the other radio communication All of the addition average values of the station apparatus perform an operation of detecting a frequency band determined as a low signal intensity equal to or lower than the threshold value as a free frequency.

A twelfth technical means determines whether or not the wireless communication station apparatus according to any one of the fourth to eleventh technical means is a free frequency in which no wireless signal exists in the vicinity of the own wireless communication station apparatus. Then, when determining the frequency band of the radio signal used for communication with the wireless terminal device, the communication method and / or transmission power amount used for the communication is also determined.

According to a thirteenth technical means, wireless communication in a wireless communication system comprising a plurality of wireless communication station devices that communicate with one or more wireless terminal devices existing in a service area using wireless signals in a frequency band assigned at the start of communication. transmitting the method, the wireless communication station apparatus, the measurement results of the measured signal strength the signal strength of the radio signal for all frequency bands of the utilization object existing around the radio communication station, the another wireless communication station to one, the measurement result of the signal strength that has been transmitted from another wireless communication station to receive the said signal strength in the measurement results and other wireless communication station of the signal strength of the radio communication station based on the measurement results, in the vicinity of the radio communication station to determine whether or not an unoccupied frequency wireless signal is not present, the determination result of determining a vacant frequency, before A wireless communication method for determining the frequency band of the radio signals used to communicate with the wireless terminal device, the radio communication station apparatus, when determining the frequency band of the radio signals used to communicate with the wireless terminal device The measurement results of the signal strength measured by the own radio communication station device and the measurement results of the signal strength of the other radio communication station device transmitted from the other radio communication station device are used for all frequency bands to be used. For each band, weight correction is performed with a weight correction value set in advance, and the signal strength measurement result of the own radio communication station apparatus subjected to the weight correction and the other radio communication station apparatus transmitted from the other radio communication station apparatus The measurement result of the signal strength is compared with a predetermined threshold value for determining a free frequency, and a determination result of the signal strength indicating whether it is a free frequency is output, and the output own radio communication station Used for communication with the wireless terminal device by performing an operation to determine whether or not the signal strength of the wireless communication station device and the other wireless communication station device is a free frequency around the own wireless communication station device. The weight correction value that is set in advance is determined based on the distance between the wireless communication station apparatuses, the degree of correlation with respect to the signal strength of the received signal between the wireless communication station apparatuses, It is determined according to any one or more of the installation location, the communication time zone of the radio communication station apparatus, and the interference occurrence history information in the past communication of the radio communication station apparatus .
The fourteenth technical means provides wireless communication in a wireless communication system comprising a plurality of wireless communication station devices that communicate with one or more wireless terminal devices existing in a service area using wireless signals in a frequency band assigned at the start of communication. In the method, the wireless terminal device measures a signal strength of a wireless signal existing around the wireless terminal device for all frequency bands to be used as a terminal measurement result of the signal strength, and a service area in which the wireless terminal device exists To the wireless communication station apparatus, and the wireless communication station apparatus receives the terminal measurement result of the signal strength transmitted from one or more of the wireless terminal apparatuses existing in a service area of the wireless communication station apparatus. While receiving the terminal measurement result of the signal strength transmitted from the other radio communication station apparatus, Based on the terminal measurement result of the signal strength of the communication station apparatus and the terminal measurement result of the signal strength of another radio communication station apparatus, whether or not the radio frequency is a free frequency in the vicinity of the own radio communication station apparatus A wireless communication method for determining a frequency band of a wireless signal used for communication with the wireless terminal device based on a determination result determined as an empty frequency, wherein the wireless communication station device includes the wireless terminal When determining the frequency band of the radio signal used for communication with the apparatus, the signal strength of the own radio communication station apparatus transmitted from one or more of the radio terminal apparatuses existing in the service area of the own radio communication station apparatus Terminal measurement result of the other wireless communication station apparatus and the terminal measurement result of the signal strength of the other wireless communication station apparatus transmitted from the other wireless communication station apparatus The weight measurement is performed by the weight correction value set in advance, and the signal measurement result of the signal strength of the own radio communication station apparatus and the signal of the other radio communication station apparatus transmitted from the other radio communication station apparatus are subjected to the weight correction. The terminal measurement result of the strength is compared with a predetermined threshold value for determining the free frequency, and the determination result of the signal strength indicating whether or not it is a free frequency is output, and the output own radio communication station apparatus and other radio communication stations A frequency band of a radio signal used for communication with the wireless terminal device by performing an operation for determining whether or not the signal strength of the device is a free frequency around the wireless communication station device. And the weight correction value set in advance is the distance between the wireless communication station devices, the degree of correlation with the signal strength of the received signal between the wireless communication station devices, the setting of the wireless communication station device It is determined according to any one or more of the location, the communication time zone of the wireless communication station device, and the interference occurrence history information in the past communication of the wireless communication station device.
According to a fifteenth technical means, wireless communication in a wireless communication system comprising a plurality of wireless communication station devices that communicate with one or more wireless terminal devices existing in a service area using wireless signals in a frequency band assigned at the start of communication. In the method, the wireless terminal device measures a signal strength of a wireless signal existing around the wireless terminal device for all frequency bands to be used as a terminal measurement result of the signal strength, and a service area in which the wireless terminal device exists Is transmitted to the wireless communication station apparatus, and the wireless communication station apparatus transmits a terminal measurement result of the signal strength transmitted from one or more of the wireless terminal apparatuses existing in a service area of the wireless communication station apparatus, For all frequency bands to be used, by averaging for each frequency band, the signal strength of the own radio communication station apparatus An average value corresponding to a fixed result is calculated, and the calculated average value is transmitted to another wireless communication station device, while the average value transmitted from the other wireless communication station device is received. The result of further averaging the addition average values of the own radio communication station apparatus and the other radio communication station apparatus is compared with a predetermined threshold value for determining a free frequency, and a radio signal is generated around the own radio communication station apparatus. A wireless communication method for determining whether a free frequency does not exist and determining a frequency band of a wireless signal used for communication with the wireless terminal device based on a determination result determined as a free frequency, the wireless communication method comprising: When determining the frequency band of the radio signal used for communication with the wireless terminal device, the communication station device calculates the average value of the own wireless communication station device calculated by the own wireless communication station device and the other wireless communication device. The added average value of the other radio communication station apparatus transmitted from the station apparatus is subjected to weight correction with a weight correction value set in advance for each frequency band for all frequency bands to be used, and the weight-corrected self-average value is obtained. A signal strength indicating whether the frequency is a free frequency by comparing a result obtained by further adding the addition average value of the wireless communication station device and the average addition value of another wireless communication station device with a predetermined threshold for determining a free frequency For determining whether or not there is a free frequency around the own radio communication station apparatus with respect to the determination result of the signal strength of the output of the own radio communication station apparatus and the other radio communication station apparatus To determine a frequency band of a radio signal used for communication with the radio terminal device, and the weight correction value set in advance is a distance between radio communication station devices. Any of the degree of correlation between the signal strengths of the received signals between the wireless communication station devices, the installation location of the wireless communication station device, the communication time zone of the wireless communication station device, and the interference occurrence history information in the past communication of the wireless communication station device It is determined according to one or more .

Wireless communication system of the present invention, according to the wireless communication station apparatus location Contact and wireless communication method, the wireless terminal device which exists in the service area of the wireless communication station or each wireless communication station device constituting a radio communication system, reception Measurement of signal strength and / or determination of signal strength indicating whether it is a vacant frequency or not, and exchange of the measurement result and / or determination result of signal strength indicating whether it is a vacant frequency between radio communication station apparatuses By using the signal strength measurement result and / or the signal strength determination result of not only the own wireless communication station device but also other wireless communication station devices, a free frequency around the own wireless communication station device is searched. , The following effects can be obtained.

  By coordinating between each wireless communication station device, the signal strength measurement result and / or the signal strength determination result indicating whether or not it is a free frequency are exchanged, so that the use target compensation around the wireless communication station device is Since the presence or absence of radio waves from other radio communication systems is determined for all frequency bands, even if radio waves from other radio communication systems are temporarily weakened due to obstruction, fading, etc., Even if there is an error in the detection accuracy of some wireless communication station devices that detect vacant frequencies such as bandpass filters, the probability of causing false detection of vacant frequencies is reduced, The detection accuracy of the vacant frequency can be increased.

  That is, according to the present invention, when detecting a radio wave of an empty frequency around the own radio communication station apparatus, the measurement result / determination result from other radio communication station apparatuses as well as the own radio communication station apparatus is taken into consideration. Even if it is an environment where the radio waves from other radio communication systems are blocked by an obstacle or fading, or if a failure or a large error occurs in a radio wave detection device, It is possible to prevent erroneous detection of an empty frequency band more reliably.

  Further, when determining the communication frequency and communication method, the measurement result of the signal strength in the other wireless communication station apparatus other than the own wireless communication station apparatus, the own wireless communication station apparatus-other wireless communication station apparatus and It is also possible to perform weighting based on the distance between the wireless communication station apparatus and the communication environment of the own wireless communication station apparatus. For example, other wireless communication station apparatuses existing within a predetermined distance threshold from the own wireless communication station apparatus Is assumed to be under the influence of shadowing that a correlation occurs with the signal strength measurement value between itself and the radio communication station device, and the weight correction value by which the signal strength measurement value is multiplied is “0” or proportional to the distance Set the propagation loss amount to be added or subtracted as a weight correction value to the measured signal strength value to a value that is inversely proportional to the predetermined value or distance. Therefore, the measurement result of the signal strength of another wireless communication station apparatus existing within the distance threshold, is also possible and to reduce the impact on the determination processing of the communication frequency and communication scheme.

  Furthermore, depending on the signal strength measurement result, not only the frequency band used for the current communication but also the optimum communication method and transmission power can be selected at the same time, minimizing the possibility of interference. It is possible to perform wireless communication at an optimal transmission rate while limiting the number of transmissions.

Hereinafter, a radio communication system according to the present invention will be described in detail with reference to the drawings an example thereof for best embodiment of a wireless communication station apparatus location Contact and wireless communication method.

(Features of the present invention)
Prior to the description of the embodiment of the wireless communication system according to the present invention, first, the outline of the features of the wireless communication system according to the present invention will be described. The radio communication system according to the present invention measures the signal strength of the received signal and / or determines the free frequency by each radio communication station device itself or each radio terminal device existing in the service area of each radio communication station device. By exchanging the measurement results and / or determination results of the wireless communication station devices constituting the wireless communication system, not only the measurement results and / or determination results of the own wireless communication station device but also other wireless communication It is also possible to search for a vacant frequency around the own radio communication station apparatus using the measurement result and / or the determination result in the station apparatus.

  Further, when determining the communication frequency and communication method, the measurement result of the signal strength in the other wireless communication station apparatus other than the own wireless communication station apparatus, the own wireless communication station apparatus-other wireless communication station apparatus and Or weighting based on the communication environment of the own radio communication station device (for example, the installation location, the communication time zone, or the shadowing environment in which the signal strength of each received signal correlates) It is possible. For example, with respect to other wireless communication station devices existing within a predetermined distance threshold Dth determined in advance from the own wireless communication station device, there is a shadowing phenomenon in which a correlation occurs with respect to the measured signal strength with the own wireless communication station device. By setting the weighting factor that multiplies the measured value of the signal strength as the weight correction value to “0” or a small value proportional to the distance, or as the weight correction value for the measured signal strength value. By setting the propagation loss amount to be added or subtracted to a predetermined value or a value inversely proportional to the distance, the measurement result of the signal strength of the radio base station existing within the range of the distance threshold Dth is determined by the communication frequency and communication method. It is possible to reduce the degree of influence on processing.

  By providing a mechanism for exchanging measurement results and / or determination results between radio communication station devices like this, all the radio communication station devices constituting the radio communication system can cooperate with each other in the entire frequency band of the target of use. Therefore, it is possible to comprehensively determine the presence / absence of radio waves in the other wireless communication system in FIG.

  Hereinafter, embodiments of the present invention will be described. The wireless communication system of the present invention includes one or more wireless communication station apparatuses that perform transmission / reception and relay of wireless signals, and each wireless communication station apparatus includes each wireless communication station apparatus. Each radio communication station apparatus performs transmission / reception and relay of radio signals using a frequency band allocated for communication at the start of communication with radio terminal apparatuses existing in a service area covered by each communication station apparatus. Communication performed with the communication partner of each wireless terminal device is relayed via a signal line provided between them or a higher-level network.

  Further, each radio communication station apparatus periodically performs an operation of searching for an unused frequency band that is not used in the vicinity of each radio communication station apparatus as a radio wave detection process for detecting an unused frequency band at a predetermined cycle. When the communication start request is received from the wireless terminal device, the frequency band, communication method and / or transmission power amount of the wireless signal used for the wireless terminal device to perform communication are processed as processing before the communication start. The operation of determining and notifying the wireless terminal device is executed.

  In the following description of each embodiment, the wireless communication system and the wireless communication method according to the present invention will be mainly described. However, the embodiment of the wireless communication station apparatus and the wireless terminal device according to the present invention constituting the wireless communication system will be described. Therefore, further explanation below in the form of taking up each of the wireless communication station device and the wireless terminal device alone will be omitted. Unless the description is ambiguous, the radio communication station apparatus of the present invention is abbreviated as a radio base station or a base station, which is a term generally used in a radio communication system, and the radio terminal apparatus of the present invention is It will be abbreviated as a wireless terminal or a terminal. Here, the radio communication station apparatus is not only a fixed installation type radio base station apparatus or radio base station apparatus that is fixedly installed in a station building or indoors, but also a portable apparatus that is movable such as on-vehicle use. It doesn't matter.

As an example of the radio communication system in each embodiment, the number of radio base stations existing in the vicinity of a specific radio base station is five, and the frequency band to be used for communication between the radio base station and the radio terminal is 2. 4 GHz-2.5 GHz band, is also assumed that 10 M Hz the width of the frequency for each band (frequency band) used for communication of the wireless terminal.

The wireless communication system of the present invention, in the following description of the embodiments relates to a wireless communication station apparatus location Contact and wireless communication method, a wireless communication system to determine the frequency band of the radio signal used for wireless communication, or, As a wireless communication system that determines not only the frequency band of a wireless signal used for wireless communication but also the communication method and / or transmission power amount, a wireless terminal device can communicate with a communication partner via a wireless communication station device. Although a case where the present invention is applied to a wireless communication mode in which communication is performed with another wireless terminal device or with another communication device will be described, the present invention is not limited to such a case.

  For example, wireless terminal devices can be connected one-to-one, one-to-n, or m without a wireless communication station device such as a wireless base station device or a wireless master station device, such as a transceiver or a high-performance portable information terminal. You may make it apply to the ad hoc communication form which mutually communicates using a radio signal between the radio | wireless terminal apparatus of n, or the radio | wireless terminal apparatus itself is provided with the relay function, and the said radio | wireless terminal A wireless signal is relayed in a bucket-relay manner from one wireless terminal device to another wireless terminal device without going through a wireless communication station device such as a wireless base station device or a wireless master station device. The present invention may be applied to various ad hoc communication modes.

  In the case of such an ad hoc communication mode, the wireless terminal device is provided with at least a function substantially equivalent to the wireless communication station device in each of the embodiments described below, and any one of the ones prior to the start of ad hoc communication. A wireless terminal device or a wireless terminal device having a relay function determines a frequency band, a communication method, and / or a transmission power amount used for the current wireless communication, and notifies each wireless terminal device related to the current communication. You can do it.

(First embodiment)
First, a first embodiment relating to a wireless communication system, a wireless communication station device (wireless base station), a wireless terminal device (wireless terminal), and a wireless communication method according to the present invention will be described. FIG. 1 is a system configuration diagram showing an example of a system configuration of a radio communication system according to the present invention. A radio communication system 100 shown in FIG. 1 includes a plurality of radio base stations (in FIG. 1, radio base stations 1, 2, 3, 4, and 5 that cover service areas 11, 12, 13, 14, and 15 respectively). Individual radio base stations), signal lines connecting the radio base stations (in FIG. 1, seven signal lines 21, 22, 23, 24, 25, 26, and 27), and a service area Consists of a plurality of wireless terminals (only three wireless terminals 31, 32, and 33 are displayed in FIG. 1) that perform communication using a wireless signal with a covered wireless base station .

  As described above, the wireless base stations 1, 2, 3, 4, and 5 communicate information with each other via any one of the signal lines 21, 22, 23, 24, 25, 26, and 27. When wireless terminals 31, 32, and 33 are present in any of service areas 11, 12, 13, 14, and 15 covered by the wireless base stations 1, 2, 3, 4, and 5 (in FIG. The terminal 31 is in the service area 13 of the radio base station 3 and the radio terminals 32 and 33 are in the service area 15 of the radio base station 5), and the radio terminals 31, 32, and 33 are respectively present It is connected to an upper network (not shown) via the wireless base stations 3 and 5 in the service areas 13 and 15 to communicate with a desired communication partner.

  Here, an example of the distance between the radio base station 1 shown in FIG. 1 and the other radio base stations 2, 3, 4, and 5 is shown in FIG. FIG. 2 is an explanatory diagram showing an example of the distance between a certain radio base station shown in FIG. 1, for example, the radio base station 1 and other neighboring radio base stations 2, 3, 4, and 5. It is assumed that the distances from 1 to the other radio base stations 2, 3, 4, and 5 are 3 km, 4 km, 2 km, and 6 km, respectively.

  FIG. 3 shows an example of a block configuration of the wireless terminal in the first embodiment of the present invention. Each of the wireless terminals 31, 32, and 33 in FIG. 1 has the same configuration as that in FIG. As shown in FIG. 3, the radio terminal 30 includes at least an antenna 30a, a radio signal processing unit 30b, a switch 30c, and a base station-terminal interface unit 30d. The radio signal processing unit 30b converts the radio signal transmitted and received by the antenna 30a into a bidirectional signal and a digital signal. The switch 30c is connected to the A side during the communication start process, and the radio signal processing unit 30b is connected to the base station-terminal interface unit 30d. On the other hand, during normal communication, the switch 30c is connected to the B side, and the radio signal processing unit 30b is connected to an upper layer processing unit (not shown).

  The base station-terminal interface unit 30d provides terminal-side transmission / reception means for transmitting / receiving information to / from a wireless base station in the service area in which the wireless terminal 30 exists. It is connected to the radio signal processing unit 30b via 30c, and at the beginning of communication, a radio base station (the radio terminal 30 is present in the service area 1 shown in FIG. 1) is transmitted via the radio signal processing unit 30b to the communication start request packet. If so, it transmits to the radio base station 1). Also, it receives a frequency indication packet from the radio base station that has received the communication start request packet, and transmits the frequency and bandwidth indicated by the frequency indication packet to the radio signal processing unit 30b as a frequency indication signal.

  Next, FIG. 4 shows an example of a block configuration of the radio base station in the first embodiment of the present invention. Each of the radio base stations 1, 2, 3, 4, and 5 in FIG. 1 has the same configuration as that in FIG. As shown in FIG. 4, the radio base station 10 includes a communication antenna 10a, a radio wave detection antenna 10b, a radio wave detector 10c, an inter-base station interface unit 10d, a communication frequency band determiner 10e, and a base station-terminal interface. It includes at least a unit 10f, a switch 10g, and a radio signal processing unit 10h.

  The radio wave detector 10c provides signal intensity measuring means for measuring the signal intensity of a radio signal existing around the radio communication station apparatus 10 for all frequency bands to be used, and is received by the radio wave detection antenna 10b. As a result, the power in the entire frequency band serving as a supplement to use of the wireless communication system 100 is measured as the signal strength (signal level). In some cases, there may be provided a vacant frequency detection means for detecting a frequency at which radio waves of other wireless communication systems do not exist from the measurement result of the signal strength.

FIG. 5 is a block configuration diagram showing an example of the configuration of the radio wave detector 10c of the radio base station 10 shown in FIG. As shown in FIG. 5, the radio wave detector 10c includes at least a quadrature demodulator 10c ₁ , a synthesizer 10c ₂ , a bandpass filter 10c ₃ , and a power measuring device 10c ₄ . The radio signal coming to the input from the radio wave detection antenna 10b, while changing the center frequency to be extracted using a synthesizer 10c _2, and demodulated by a quadrature demodulator 10c _1, the signal power of the output signal of the bandpass filter 10c ₃ measured by a power measurement device 10c ₄ as the signal intensity (signal level).

The inter-base-station interface unit 10d of the radio base station 10 in FIG. 4 provides a communication means for transmitting and receiving information to and from each other between radio base stations, that is, between radio communication station apparatuses, and the radio station transmitted from the radio wave detector 10c. The measurement result of the signal power is obtained from another radio base station located in the vicinity via the signal line (in the case of the radio base station 1 in FIG. 1, the other radio base station 2 via the signal lines 21, 23, 24). , 3, 4, 5). Moreover, (the case in Figure 1 of the radio base station 1, the other wireless base station 2, 3, 4, 5) another radio base station a measurement result of the power or signal strength of a radio signal which has been transmitted from Figure 4 to the communication frequency band determiner 10e of the radio base station 10.

  The communication frequency band determiner 10e detects a frequency at which radio waves of other radio communication systems do not exist based on the measurement result of the signal intensity from the radio wave detector 10c as signal intensity measuring means or depending on the case. Based on the detection result of the vacant frequency from the radio wave detector 10c as the vacant frequency detecting means, that is, the radio signal used for the current communication of the radio terminal so as to perform communication using the frequency at which no radio wave exists. Use frequency determining means for determining a frequency band, or depending on the case, from the free frequency detection result in the own wireless communication station device and the free frequency detection result transmitted from another wireless communication station device The present invention provides vacant frequency determining means for determining the presence or absence of radio waves of other systems in the vicinity.

  In the present embodiment, the communication frequency band determiner 10e includes the measurement result of the power of the radio signal transmitted from the radio wave detector 10c and other radio base stations (in the case of the radio base station 1 in FIG. Based on the measurement result of the power of the radio signal transmitted from the base station 2, 3, 4, 5), a free frequency band in which no radio wave of another radio communication system exists is determined, and the radio base station 10 determines the frequency and bandwidth to be used for the current communication at 10 and transmits the frequency response signal to the frequency inquiry from the base station-terminal interface unit 10f to the base station-terminal interface unit 10f. Further, the communication frequency band determiner 10e transmits the frequency instruction signal indicating the frequency and bandwidth used for the current communication to the radio signal processing unit 10h. The communication frequency band determiner 10e manages the frequency and bandwidth used by each wireless terminal existing in the service area covered by the wireless base station 10.

FIG. 6 is a block configuration diagram showing an example of the configuration of the communication frequency band determiner 10e of the radio base station 10 shown in FIG. As shown in FIG. 6, the communication frequency band determiner 10e is configured to include at least a comparator 10e ₁ , a logical product operator 10e ₂ , and a frequency determiner 10e ₃ .

The comparator 10e ₁ is a measurement result of the signal strength of the radio signal measured by the radio wave detector 10c, and compared with a predetermined threshold value for the empty frequency determination, the determination result of the signal strength indicating whether vacant frequency The determination means for outputting is provided, and the radio wave of the other system around the own radio communication station apparatus from the available frequency detection result in the own radio communication station apparatus and the available frequency detection result transmitted from the other radio communication station apparatus. A vacant frequency determination means for determining the presence or absence of the presence of the. That is, the comparator 10e _1, the determination indicating whether or not the the radio signal of the power i.e. comparison and compared with a predetermined threshold value the measurement results of the signal strength as a free frequency determination result (unoccupied frequency output from a radio wave detector 10c Result) and a comparison result (determination result indicating whether or not it is an empty frequency) by comparing the measurement result of the power of the radio signal transmitted from another radio base station, that is, the signal strength, with a predetermined threshold for determining the empty frequency. , Output for each band.

The logical product operator 10e ₂ uses the signal strength determination result of the own wireless base station 10 and the signal strength determination result of the other wireless base station output from the comparator 10e _{1 in the} vicinity of the own wireless communication station device. A signal obtained as a result of performing calculation for determining whether or not the frequency is a vacant frequency, or comparing the measurement result of the signal strength with the threshold value instead of transmitting the measurement result of the signal strength by the radio wave detector 10c. While transmitting the strength determination result to another wireless communication station device, the signal strength determination result transmitted from the other wireless communication station device is received and the signal strength measurement result of the other wireless communication station device is received. Instead of receiving by the communication means, the determination result of the signal strength of the own wireless communication station device and the determination result of the signal strength of the other wireless communication station device in the vicinity of the own wireless communication station device There is provided a calculation means for performing an operation for determining whether the come frequencies.

In this embodiment, the comparator 10e ₁ signal strength comparison result in the radio base station which is output from the (judgment result indicating whether or not an unoccupied frequency) and the comparison result of the signal strength at the other base station (free frequency By calculating the logical product of all the comparison results with the determination result indicating whether or not) for each band, the frequency and bandwidth indicating a low signal intensity below a predetermined threshold in all the comparison results can be set to an empty frequency band. Extract as L (m). In other words, the AND operator 10e ₂ uses the signal strength determination results for all the frequency bands to be used as the vacant frequency determination results for all the signal strength measurement results of the own radio base station 10 and other radio base stations. As long as it is a calculation means for detecting a frequency band determined as a low signal intensity equal to or less than a predetermined threshold as an empty frequency, and any calculation means for calculating such an empty frequency detection, as in this embodiment It is not limited to the logical product operation.

Further, the frequency determiner 10e ₃ determines the signal strength determination result of the comparator 10e ₁ and all the radio base stations (including the radio base station 10 and radio base stations located in the vicinity thereof) of the logical product calculator 10e ₂ . It is intended to determine the frequency band of the radio signal used to communicate the current wireless terminal from the determination result of the signal strength in the radio base station), based on a free frequency band L (m) output from the logical product operation unit 10e ₂ Next, the frequency and bandwidth used for the current communication of the wireless terminal 30 that is the transmission source of the communication start request packet are determined, and the base station-terminal is used as a frequency response signal in response to the frequency inquiry from the base station-terminal interface unit 10f. The radio signal processing unit 10 is transmitted as a frequency instruction signal that is transmitted to the inter-interface unit 10f and indicates the frequency and bandwidth used for the current communication. to h.

  The base station-terminal interface unit 10f of the radio base station 10 in FIG. 4 transmits / receives information to / from a radio terminal (radio terminal 30 shown in FIG. 3) existing in the service area of the radio communication station apparatus 10. A control packet for generating a control packet to be transmitted to a radio terminal existing in the service area of the radio base station 10 and for decoding a control packet received from the radio terminal. Packet processing means is provided. When the communication start request packet is received from the wireless terminal, based on the decoding result, the communication frequency band determiner 10e is inquired about the frequency band to be used for the current communication. From the communication frequency band determiner 10e, When the frequency response signal indicating that the frequency and the bandwidth are determined is received, a frequency instruction packet indicating the frequency and band radiation used for communication is generated, and the switch 10g is transmitted to the wireless terminal that is the source of the communication start request packet. And transmitted via the wireless signal processing unit 10h.

  During the communication start process, the switch 10g is connected to the A side to connect the base station-terminal interface unit 10f and the radio signal processing unit 10h. On the other hand, at the time of normal communication, switching to the B side, connecting the radio signal processing unit 10h and a higher-level network (not shown), the frequency indicated by the frequency indication signal from the communication frequency band determiner 10e Communication is performed between the wireless terminal and the network via the wireless signal processing unit 10h set to the bandwidth.

  The radio signal processing unit 10h provides a signal processing means for bidirectionally converting a communication radio signal transmitted / received to / from the wireless terminal 30 via the communication antenna 10a and a digital signal transmitted / received to / from the network. At the start of communication processing, control packets to be transmitted / received to / from the wireless terminal 30 are exchanged with the base station-terminal interface unit 10f, and during normal communication with the wireless terminal 30. Communication packets to be transmitted and received are exchanged with the network.

  Hereinafter, with respect to the present embodiment using the radio terminal 30 and the radio base station 10 configured as shown in FIG. 3 and FIG. 4, the frequency and bandwidth of the radio signal used for communication in the radio base station 1 shown in FIG. Processing will be described with reference to the flowcharts of FIGS. 7 and 10 showing an example of the wireless communication method of the present invention. As described above, the configuration of the radio terminal includes the configuration of the radio terminal 30 as shown in FIG. 3, and as described above, the configuration of the radio base station 1 includes the radio base station 10 as shown in FIG. It shall consist of the following.

  In this embodiment, in the radio base station 1, a series of processes from radio wave detection processing for measuring the signal strength of a radio signal and detection of a frequency band used for communication to the start of communication in order to detect a vacant frequency of the radio signal. The two processes of the communication start process for performing the above process are performed. The radio wave detection process is periodically executed at a predetermined cycle, and the communication start process is executed with a communication start request from a communication start request packet from a wireless terminal as a trigger.

  First, an example of radio wave detection processing in the present embodiment of the radio base station 1 will be described with reference to FIG. FIG. 7 is a flowchart illustrating an example of radio wave detection processing in each radio base station according to the first embodiment of this invention.

In FIG. 7, first, setting is made so as to time until a predetermined time period using a timer synchronized between all radio base stations (step S1). Until the timer reaches a predetermined time limit (no in step S3), the decrement processing is performed at the timing synchronized with all the radio base stations (step S2). When the timer expires (yes in step S3) The radio wave detection process is started. Here, the center frequency of the band-pass filter 10c ₃ in radio detector 10c shown in FIG. 5, can be set arbitrarily in the 2.4GHz-2.5 GHz band, bandwidth, and what is 10MHz To do.

When the radio wave detection process in the radio wave detector 10c is started, the radio wave detector 10c has a plurality of bands (in this embodiment, 10 bands) having a frequency band of 2.4 GHz to 2.5 GHz having a width of 10 MHz. until delimiting the band), the center frequency of the bandpass filter 10c ₃ is, between the 2.405GHz the center frequency of each band up to 2.495GHz, i.e., to complete the measurement of the signal strength of the entire frequency band (No in step S5) The center frequency is sequentially changed in increments of 10 MHz (step S6), and the power measuring device 10c ₄ measures the power of each band for the radio signal received by the radio wave detection antenna 10b as the signal strength ( Step S4).

  Here, as shown in FIG. 8, when the 2.4 GHz-2.5 GHz band is assigned with band numbers 1 to 10 in order every 10 MHz, the radio base stations 1, 2, 3, and 4 shown in FIG. Suppose that the measurement results of the signal intensity as shown in FIG. 9 are obtained. FIG. 8 is an explanatory diagram when band numbers are assigned to the 2.4 GHz-2.5 GHz band every 10 MHz, and band numbers 1, 2, 3,... Assigned. FIG. 9 shows the measurement results of the power, that is, the signal strength for each band number in each radio base station shown in FIG. 1 (radio base stations 1, 2, 3, and 4 in this embodiment) in this embodiment. It is a table showing the determination results, and the determination value of the free frequency obtained from the comparison result between the measured value [dBm] measured by using the power of each band number as the signal strength and the threshold value determined in advance for determining the free frequency is also shown. is doing.

  When the measurement of the signal strength in all frequency bands is completed (yes in step S5), the signal strength measurement result is then transmitted to other radio base stations via the signal lines 21,..., 27 shown in FIG. Are exchanged (step S7). Here, the radio base station exchanging the measurement results is a neighboring radio base station existing in a circle with a radius of 5 km, centering on the own radio base station. That is, in the case of the radio base station 1, as shown in FIG. 2, when the signal strength measurement result is transmitted to the radio base stations 2, 3, and 4 that exist within 5 km from the radio base station 1. At the same time, signal strength measurement results are received from each of the radio base stations 2, 3 and 4.

  In the radio base station 1, the measurement results of the signal strength of the radio base station 1 itself and the measurement results from the radio base stations 2, 3 and 4 existing in a circle with a radius of 5 km are as shown in FIG. 9, the measurement result of the signal strength as shown in FIG. 9 is input to the communication frequency band determiner 10e. In the communication frequency band determiner 10e, based on the measurement results of the signal strength at a plurality of radio base stations of the own radio base station 1 and other radio base stations 2, 3, and 4 in the vicinity within a distance of 5 km, A free frequency band that is not currently used in the vicinity of the wireless base station 1 is extracted, and a free frequency band that is used for the current communication by the wireless terminal that has transmitted the communication start request packet is determined.

  Next, in the present embodiment of the radio base station 1 having the configuration of the radio base station 10 of FIG. 4, an example of an operation for performing communication start processing of the radio terminal will be described with reference to FIG. FIG. 10 is a flowchart illustrating an example of an operation of performing communication start processing of the wireless terminal 30 in the wireless base station 1 according to the first embodiment of this invention, and a square box indicates processing on the wireless base station 1 side. A box with rounded corners indicates processing on the wireless terminal side.

  As shown in FIG. 10, a wireless terminal requesting the start of communication starts communication with the wireless base station 1 in the service area 11 where the wireless terminal exists before connecting to the network and starting communication. An operation of transmitting a request packet and receiving a frequency instruction packet indicating a frequency band to be used for the current communication from the radio base station 1 is performed. In the transmission / reception operation of the communication start request packet and the frequency instruction packet, as a communication channel for transmitting / receiving a control packet between the wireless base station and the wireless terminal, the frequency band and communication method are the same as those of the wireless base station and the wireless terminal. It is assumed that it is determined in advance with the terminal.

  First, the wireless terminal having the configuration of the wireless terminal 30 in FIG. 3 and requesting the start of communication transmits a communication start request packet as described above via the base station-terminal interface unit 30d in FIG. 4 is transmitted to the radio base station 1 having the configuration of 4 radio base stations 10 (step S11). When the radio base station 1 receives the communication start request packet from the radio terminal 30 via the radio base station-terminal interface unit 10f shown in FIG. 4 (step S12), the radio frequency base station 10e uses the radio base station 1 to transmit the radio base station 1 The process of determining the frequency band used by the terminal for this communication is performed according to the following procedure (step S13).

As shown in FIG. 9, the own and other radio base stations (in this embodiment, the own radio base station is a radio base station 1 and the other radio base station is a radio base station 2 within a distance of 5 km from the radio base station 1. 3,4) measurement results of the measured signal strength in is input to the communication frequency band determiner 10e, firstly, the comparator 10e ₁ of the communication frequency band determiner 10e, and predetermined as a free frequency determination Compared with a threshold value, a band lower than the threshold value is determined as a free frequency band. Here, as described above, the threshold value for determining the free frequency is set to, for example, −120 dBm. Comparator 10e subjective and each radio base station as a result of comparison ₁ comparison result namely the judgment result of the available frequency with a threshold eg -120dBm in (the radio base station 1, 2, 3, 4 in this embodiment) is As shown in the comparison column with the threshold value in FIG. In the comparison column with the threshold value in FIG. 9, the band displayed as “vacant” indicates that the band is a vacant frequency band having a low signal intensity equal to or less than the threshold value, for example, −120 dBm.

Then, the determination result of the idle frequency as shown in FIG. 9, input to the logical product operation unit 10e ₂ of the communication frequency band determiner 10e. Here, when it is determined that the free frequency band is a threshold value, for example, −120 dBm or less, the determination result D = 1, and when the free frequency band is not determined, the determination result D = 0 is expressed. For each band of 2.4 GHz to 2.5 GHz, when the AND operation is performed on the determination result of the own / other radio base station, the band where the AND operation result is “1” This means that all of the stations are bands in which the signal strength is a low signal strength that is equal to or lower than a threshold value, and there are no radio waves of other wireless communication systems around the wireless base station 1. Therefore, it can be regarded as a vacant frequency band.

In general, the determination result of the band m in the radio base station 1 is D (1, m), and the determination of the band m in the radio base station 2 is performed on the determination results of the total n radio base stations of the own and other radio base stations. If the result is D (2, m), the determination result of the band m at the radio base station 3 is D (3, m),..., And the determination result of the band m at the radio base station n is D (n, m) The logical product L ₁ (m) for the band m in the base station 1 is
L ₁ (m) = D (1, m) · D (2, m) · D (3, m) ··· D (n, m) (1)
As given.

Here, as a determination result of the band m in the radio base station i (i = 1 to n), as described above, when the band is determined to be a free frequency band, the determination result D (i, m) = 1, the empty If it is not determined that the frequency band, and the determination result D (i, m) = 0, the band m in which L ₁ (m) is “1” is transmitted to other wireless base station 1 in the vicinity of the wireless base station 1. Since there is no radio wave of the communication system, no interference occurs and it can be regarded as an empty frequency band. When the determination result as shown in FIG. 9 is obtained, the following result is obtained based on the equation (1).

L ₁ (1) = D (1,1) · D (2,1) · D (3,1) · D (4,1)
= 0, 0, 0, 0 = 0
L ₁ (2) = 0, 0, 0, 0 = 0
L ₁ (3) = 1 · 0 · 0 · 0 = 0
L ₁ (4) = 1 · 1 · 0 · 0 = 0
L ₁ (5) = 1 · 1 · 1 · 1 = 1
L ₁ (6) = 0 · 1 · 1 · 1 = 0
L ₁ (7) = 0 · 0 · 0 · 0 = 0
L ₁ (8) = 0 · 0 · 0 · 0 = 0
L ₁ (9) = 0 · 0 · 0 · 1 = 0
L ₁ (10) = 0 · 0 · 1 · 1 = 0
From the calculation result of the logical product as described above, in the communication frequency band determiner 10e frequency determiner 10e ₃ of the wireless base station 1, regarded as a frequency band is empty band number 5. Therefore, the frequency determiner 10e ₃ consists consisting of the communication frequency band determiner 10e of the wireless base station 1 in the radio base station 10 of FIG. 4, the center frequency 2.445GHz band number 5, the bandwidth 10 MHz, the communication start It determines to use for communication with the radio | wireless terminal 30 which transmitted the request packet, and sets the frequency and the bandwidth of the radio | wireless signal processing part 10h shown in FIG. Further, as shown in the flowchart of FIG. 10, at the same time, the frequency instruction packet storing the frequency / bandwidth information determined to be used for communication of the wireless terminal 30 is stored via the base station-terminal interface unit 10f. The communication start request packet is transmitted to the wireless terminal 30 that is the transmission source (step S14). The wireless terminal 30 receives this frequency instruction packet (step S15), sets the frequency / bandwidth of the wireless signal processing unit 30b shown in FIG. 3, and starts communication.

  That is, the measurement result of the signal strength of the radio signal measured by the radio wave detector 10c that provides the signal strength measurement means is displayed in the vicinity of the vicinity by the inter-base station interface unit 10d that provides the communication means for performing communication between the radio base stations. While transmitting to the other radio communication station apparatus, the measurement result of the signal strength of the radio signal transmitted from the other radio communication station apparatus is received by the inter-base station interface unit 10d, and the frequency band used for communication is determined. The measurement result of the signal strength of the radio signal measured by the radio wave detector 10c of the own radio base station 10 and the other received by the inter-base station interface unit 10d by the communication frequency band determinator 10e providing the used frequency determining means Based on the measurement result of the signal strength of the radio signal transmitted from the radio communication station apparatus It is determined whether or not the line signal is an unused frequency, and the frequency band of the wireless signal used for communication with the wireless terminal that is the transmission source of the communication start request packet is determined based on the determination result determined as the unused frequency. .

By performing the operation as described above, the radio base station 1 not only measures the signal strength of each band in the radio base station 1 but also within a distance of, for example, 5 km as the frequency band of the radio signal used for this communication. Using the measurement results of the signal strength of each band in the other radio base stations 2, 3 and 4 located in the vicinity of the signal, the measurement result of the signal strength is compared with a predetermined threshold for vacant frequency determination, In both of its own and all other radio base stations, a mechanism is adopted that decides to use a band with a low signal strength below the threshold as a frequency band for communication this time. The reception level of the radio wave from the radio communication system is temporarily weakened due to shielding or fading by an obstacle, or the band-pass filter 1 of the radio wave detector 10c. etc. c _3, even an error in the detection precision of an instrument portion of the radio base station for detecting a free frequency in some cases you are or occur, the probability of causing erroneous detection of the vacant frequency in one neighboring radio base station , And the detection accuracy of the vacant frequency can be increased.

In this embodiment, the radio base station 1 exchanges signal strength measurement results for each band as information on signal strength exchanged with other neighboring radio base stations 2, 3, and 4. Although a suitable example has been shown, the present invention is not limited to such a case. For example, as the information about the signal strength exchanged with other radio base stations 2, 3, 4 in the vicinity, in the comparator 10e ₁ of the communication frequency band determiner 10e in each of the radio base station, the measurement of the signal strength An empty frequency determination result (that is, information shown in the comparison column with the threshold value in FIG. 9), which is a result of comparing the result with a threshold value, for example, −120 dBm, may be exchanged instead of the signal strength measurement result. Alternatively, in some cases, both the signal strength measurement result and the determination result may be exchanged. If mutually exchange determination result, the determination result has been transmitted from another wireless base station may be configured to directly input to the logical product operation unit 10e ₂ of the communication frequency band determiner 10e.

(Second embodiment)
Next, a second embodiment relating to a wireless communication system, a wireless communication station device (wireless base station), a wireless terminal device (wireless terminal), and a wireless communication method according to the present invention will be described. Unlike the first embodiment, this embodiment shows a case where radio wave detection processing, that is, measurement of signal intensity and comparison of measurement result threshold values are performed not on the radio base station side but on the radio terminal side. is there.

  In this embodiment, the system configuration of the wireless communication system and the distance between the wireless base stations are the same as those in FIGS. 1 and 2, respectively. The configuration of the wireless terminal of this embodiment is shown in FIG. FIG. 11 is a block diagram showing an example of a block configuration of a wireless terminal in the second embodiment of the present invention, and shows a configuration example different from the wireless terminal 30 shown in FIG. 3 as the first embodiment. is there.

  The radio terminal 30A shown in FIG. 11 further includes a radio wave detector 30e, a comparator 30f, and a switch 2 30g in addition to the radio terminal 30 shown in FIG. The switch 1 30c of the wireless terminal 30A shown in FIG. 11 is the same as the switch 30c shown in FIG. 3, and is connected to the A side at the time of radio wave detection processing and communication start processing, and the wireless signal processing unit 30b is Connected to the base station-terminal interface unit 30d and connected to the B side during normal communication, and the radio signal processing unit 30b is connected to an upper layer processing unit (not shown).

  The configuration of the radio wave detector 30e is exactly the same as that of the radio wave detector 10c shown in FIG. 5 provided on the radio base station 10 side in the first embodiment. The signal strength measuring means for measuring the signal strength (power) of the wireless signal existing around the wireless terminal 30A in the entire frequency band as the terminal measurement result of the signal strength for each band is provided. The switch 2 30g is connected to the C side during radio wave detection processing, and the antenna 30a is connected to the radio wave detector 30e. On the other hand, during communication start processing and normal communication, the switch 2 30g is connected to the D side, and the antenna 30a is connected to the radio signal processing unit 30b.

The comparator 30f is similar to the comparator 10e ₁ provided in the communication frequency band determiner 10e of the radio base station 10 side in the first embodiment, the terminal measurement results of the measured signal strength by a radio wave detector 30e Is compared with a predetermined determination threshold value for vacant frequency determination, and a terminal-side determination means for outputting a signal strength determination result indicating whether or not the frequency is a vacant frequency as a terminal determination result of the signal strength is provided.

  The base station-terminal interface unit 30d provides terminal-side transmission / reception means for transmitting / receiving information to / from a wireless base station in the service area in which the wireless terminal 30 exists, and is output from the comparator 30f during radio wave detection processing. The signal strength determination result is transmitted to the radio base station.

  Next, an example of the configuration of the radio base station in the present embodiment is shown in FIG. FIG. 12 is a block configuration diagram showing an example of a block configuration of a radio base station in the second embodiment of the present invention. The radio base station 10A shown in FIG. 12 deletes the radio wave detection antenna 10b and the radio wave detector 10c from the radio base station 10 shown in FIG. 4, and determines a communication frequency band instead of the communication frequency band determiner 10e. 10eA is provided. Each of the radio base stations 1, 2, 3, 4 and 5 in FIG. 1 has the same configuration as that in FIG.

An example of the configuration of the communication frequency band determiner 10eA installed in the radio base station 10A of FIG. 12 is shown in FIG. FIG. 13 is a block configuration diagram showing an example of the configuration of the communication frequency band determiner 10eA of the radio base station 10A shown in FIG. As shown in FIG. 13, a communication frequency band determiner 10eA, which is a use frequency determining means for determining a frequency band of a radio signal used for communication with a wireless terminal, is transmitted from the communication frequency band determiner 10e shown in FIG. The configuration is such that the comparator 10e ₁ is deleted, and at least the AND operator 10eA ₁ and the frequency determiner 10eA ₂ are included.

  In this embodiment, since the own radio base station 10A is not equipped with the radio wave detector 10c, the power of the radio signal, that is, the signal intensity is not detected on the own radio base station 10A side, and the radio base station 10A Compared with a determination threshold value on the terminal side that is detected on the wireless terminal side having a configuration such as the wireless terminal 30A in FIG. 11 existing in the service area and that is determined in advance in the comparator 30f on the wireless terminal 30A side for vacant frequency determination. The terminal determination result of the signal strength that is the result of the input is input from the base station-terminal interface unit 10f that is a station apparatus side transmitting / receiving unit that transmits / receives information to / from the wireless terminal 30A existing in the service area of the wireless base station 10A. Come.

Therefore, the logical product operator 10eA ₁ is different from the logical product operator 10e ₂ of FIG. 6 of the first embodiment in that the wireless terminal transmitted from the wireless terminal existing in the service area of the own wireless base station 10A. Comparison result of signal power (terminal determination result of signal strength indicating whether or not free frequency is used) and comparison result of signal power of radio signal transmitted from other radio base station (signal strength indicating whether or not free frequency is used) A calculation means is provided for determining whether or not the frequency is a free frequency around the own radio base station 10A by calculating a logical product of all comparison results (terminal determination results of signal strength) with terminal determination results). In all the determination results, a frequency and a bandwidth indicating a low signal intensity (signal level) equal to or lower than a predetermined threshold are extracted as an empty frequency band L ′ (m).

Note that the determination result from the wireless terminal (terminal determination result of the signal strength) is periodically input from the base station-terminal interface unit 10f via the frequency determiner 10eA ₂ as described above, and is transmitted to other wireless base stations. The comparison result from the station (signal strength terminal determination result) is periodically input from the inter-base station interface unit 10d.

Here, the logical product operator 10eA ₁ uses the signal strength transmitted from one or a plurality of radio terminals existing in the service area of the radio base station 10A regarding the determination result of the signal strength for all frequency bands to be used. A determination result output for performing a determination to determine whether or not each frequency band is a free frequency for all frequency bands to be used, and outputting the result as a signal strength determination result in the own radio base station 10A In addition to providing a means, a frequency band in which all signal strength measurement results in the own radio base station 10A and other radio base stations are determined to be a low signal strength that is equal to or less than a predetermined threshold for vacant frequency determination is defined as a vacant frequency. Calculation means for performing calculation for determining whether or not the frequency is a free frequency around the radio base station 10A It is also possible to adopt a configuration that provides

In the present embodiment, the AND operator 10eA ₁ has both functions of the determination result output means and the calculation means, and the terminal determination result of the signal strength determined individually by each wireless terminal is transmitted to another wireless base station. A case will be described as an example in which the signal strength determination result at the radio base station, which is the output of the determination result output means, is exchanged instead of being exchanged with the other. Incidentally, the logical about product calculating unit 10eA ₁ as long as it satisfies the function relating to the determination result output means and arithmetic means for performing an operation for such vacant frequency detection is not limited to the logical AND operation as in this embodiment .

The determination result of the signal strength in the own radio base station 10A determined by the determination result output means is transmitted to another radio base station by the inter-base station interface unit 10d, while the signal strength determination result is transmitted from the other radio base station. The signal strength determination result in the radio communication station apparatus is received by the inter-base station interface unit 10d, and together with the signal strength determination result in the own radio base station 10A determined by the determination result output means, the AND operator 10eA ₁ is input to the calculation means side, and whether the signal intensity measurement results in the own radio communication station apparatus and the other radio communication station apparatus are free frequencies around the own radio communication station apparatus by the calculation means. It will be judged.

In addition, the frequency determiner 10eA ₂ uses the AND unit 10eA ₁ to calculate the signal strength in all the radio base stations (including all the radio base stations including the radio base station 10 and a radio base station located nearby). From this determination result, the frequency band of the radio signal used for communication of the current radio terminal is determined.

The frequency determiner 10eA ₂ uses the available frequency band L ′ (m) output from the AND operator 10eA ₁ and the frequency used for the current communication with the wireless terminal 30A that is the transmission source of the communication start request packet. The bandwidth is determined and transmitted to the base station-terminal interface unit 10f as a frequency response signal in response to the frequency inquiry from the base station-terminal interface unit 10f, and further, the frequency used for the current communication and the frequency indicating the bandwidth An instruction signal is transmitted to the wireless signal processing unit 10h. As described above, the frequency determiner 10eA ₂ uses the base station-terminal interface unit 10f based on the comparison result received from the wireless terminal by the base station-terminal interface unit 10f (determination result indicating whether or not the frequency is free). also it has the ability to relay to the logical product operation unit 10eA ₁ from.

  In the following, with respect to the present embodiment using the radio terminal 30A and the radio base station 10A configured as shown in FIG. 11 and FIG. 12, the frequency and bandwidth of the radio signal used for communication in the radio base station 1 shown in FIG. The processing will be described with reference to the flowcharts of FIGS. 14 and 10 showing an example of the wireless communication method of the present invention. As described above, the configuration of the radio terminal includes the configuration of the radio terminal 30A as shown in FIG. 11, and the configuration of the radio base station 1 as described above includes the radio base station 10A as shown in FIG. It shall consist of the following.

  In the present embodiment, in the radio terminal 30A, radio wave detection processing for measuring the signal strength of the radio signal is performed in order to detect the vacant frequency of the radio signal, and in the radio base station 1 configured by the radio base station 10A, A communication start process for performing a series of processes from determination of a frequency band used for communication to the start of communication is performed. The radio wave detection process in the wireless terminal 30A is periodically executed at a predetermined cycle, and the communication start process is executed with a communication start request from a communication start request packet from the wireless terminal as a trigger.

  First, an example of radio wave detection processing in the present embodiment of the wireless terminal 30A for detecting a vacant frequency of a wireless signal will be described with reference to FIG. FIG. 14 is a flowchart showing an example of the radio wave detection process in each wireless terminal according to the second embodiment of the present invention. The radio terminal side performs almost the same process as the radio wave detection process in the radio base station described in FIG. Done.

In FIG. 14, first, setting is made so as to time until a predetermined time period using a timer synchronized with the wireless base station 1 in the service area in which the wireless terminal 30A exists (step S21). Until the timer reaches a predetermined time limit (no in step S23), a decrease process is performed at a timing synchronized with the radio base station 1 (step S22), and when the timer expires (yes in step S23), The radio wave detection process is started. Here, the timer is for synchronization among all base stations have been taken, the center frequency of the bandpass filter 10c ₃ shown in FIG. 5 in the wave detector 30e provided in the radio terminal 30A side Can be arbitrarily set in the 2.4 GHz-2.5 GHz band, and the bandwidth is assumed to be 10 MHz.

When the radio wave detection process in the radio wave detector 30e is started, the radio wave detector 30e uses a plurality of bands (10 in the present embodiment) having a frequency band of 2.4 GHz-2.5 GHz as candidates for use and having a width of 10 MHz. until delimiting the band), the center frequency of the bandpass filter 10c ₃ is, between the 2.405GHz the center frequency of each band up to 2.495GHz, i.e., to complete the measurement of the signal strength of the entire frequency band (No in step S25) The center frequency is sequentially changed by 10 MHz (step S26), and the power measurement shown in FIG. 5 in the radio wave detector 30e is performed using the power of each band as the signal strength for the radio signal received by the antenna 30a. Measurement is performed by the instrument 10c ₄ (step S24).

  Further, the comparator 30f of the wireless terminal 30A compares the predetermined threshold value for determining the vacant frequency with a predetermined threshold value, and the band below the determination threshold value is determined as the vacant frequency band as the terminal determination result of the signal strength. Here, the determination threshold value for determining the free frequency is set to −120 dBm as described above. When the determination of the free frequency band is completed over the entire frequency band (yes in step S25), the terminal determination result (the comparison result in the terminal) of the signal strength of the entire frequency band is obtained in the base station-terminal interface unit 30d. The determination result notification packet is edited and transmitted to the radio base station 1 (step S27). When the base station-terminal interface unit 10f receives the determination result notification packet periodically transmitted from one or more wireless terminals existing in the service area at a predetermined cycle, the wireless base station 1 The terminal determination result of the signal strength in the wireless terminal included in the notification packet is transmitted to the communication frequency band determiner 10eA.

  Here, in the case where the number of wireless terminals existing in the service area of the own wireless base station 10A (in this embodiment, wireless base station 1) is eight terminals 1 to 8, radio wave detectors of the wireless terminals. If the terminal measurement result of the signal strength at 30e is as shown in FIG. 15, the comparison result (determination result) with the determination threshold value, for example, −120 dBm, in the comparator 30f of each wireless terminal is as shown in FIG. FIG. 15 is a table showing the terminal measurement result of the power for each band number, that is, the signal strength, in each wireless terminal existing in the service area of the wireless base station 1 that has received the communication start request from the wireless terminal in this embodiment. FIG. 16 is a table showing terminal determination results of power for each band number, that is, signal strength, in each wireless terminal existing in the service area of the wireless base station that has received the communication start request from the wireless terminal.

Next, in the present embodiment of the radio base station 1 having the configuration of the radio base station 10A of FIG. In the present embodiment, the operation of the radio base station 1 that performs the communication start process of the radio terminal 30A is substantially the same as the flowchart of FIG. a wave detector 10c and not include the comparator 10e _1, terminal determination result of the signal strength is different in that it has been transmitted from the wireless terminal.

  First, the wireless terminal that has the configuration of the wireless terminal 30A in FIG. 11 and requests the start of communication sends a communication start request packet to the wireless base station in FIG. 12 via the base station-terminal interface unit 30d in FIG. It transmits with respect to the wireless base station 1 which consists of 10A structure (step S11). When the radio base station 1 receives the communication start request packet from the radio terminal 30A via the radio base station-terminal interface unit 10f in FIG. 12 (step S12), the radio frequency station determiner 10eA performs the radio communication. The process for determining the frequency band used by terminal 30A for the current communication is performed according to the following procedure (step S13).

In the communication frequency band determiner 10eA of the radio base station 1 having the configuration of the radio base station 10A in FIG. 12, first, terminals periodically transmitted from each radio terminal existing in the service area of the radio base station 1 receiving side of the comparison result (terminal determination result of the signal strength indicating whether vacant frequency), the logic of the aND operation unit 10eA ₁ of Figure 13 the comparison result of each wireless terminal (terminal determination result of the signal strength) Find the product.

  Here, regarding the radio base station 1 having the configuration of the radio base station 10A, in the terminal determination result of the signal strength periodically transmitted from each radio terminal, it is determined as an empty frequency band as being a determination threshold, for example, −120 dBm or less. If it is determined that the determination result D = 1, and if it is not determined to be an empty frequency band, the determination result D = 0 is expressed in each wireless terminal for each band of 2.4 GHz to 2.5 GHz. When the logical product operation is performed on the signal strength terminal determination result, the band in which the logical product operation result is “1” is the same band as the low signal strength determination result equal to or lower than the threshold value in the wireless base station 1, that is, a free space. It can be regarded as a frequency band. In other words, the band in which the logical product operation result is “1” is a low signal whose signal strength measurement result of the radio signal is lower than the determination threshold value, for example, −120 dBm, in all the radio terminals existing in the service area of the radio base station 1. This means that it is a strong band, and it can be determined that there are no radio waves of other wireless communication systems in the vicinity of the own wireless base station 1.

That is, in general, for a case where a total of n radio terminals exist in the service area of the own radio base station 1, the determination result of the band m in the radio terminal 1 is D (1, m), and the radio terminal 2 Assume that the determination result of band m is D (2, m), the determination result of band m in wireless terminal 3 is D (3, m),..., And the determination result of band m in wireless terminal n is D (n, m). The logical product L ₁ (m) relating to the band m of each wireless terminal existing in the service area of the own wireless base station 1 obtained by the function of the determination result output means in the logical product calculator 10eA ₁ is:
L ₁ (m) = D (1, m) · D (2, m) · D (3, m) ···· D (n, m) (2)
As given.

Here, as a terminal determination result of the signal strength of the band m in each wireless terminal i (i = 1 to n), as described above, when it is determined that the band is a free frequency band, the determination result D (i, m) = 1, if the band is not determined to be a free frequency band, and the determination result D (i, m) = 0, the band m in which the logical product L ₁ (m) is “1” is the radio base station 1 Since there are no radio waves from other wireless communication systems in the vicinity, no interference occurs and it can be regarded as an empty frequency band.

Furthermore, the logical product with the functions of the arithmetic unit in the arithmetic unit 10eA _1, a radio base within distance 5km from the radio base station 1 in the other radio base station (in this embodiment located in the vicinity of the radio base station 1 Result of signal strength transmitted from the stations 2, 3, 4) (result of logical product of terminal determination results of signal strength of each wireless terminal existing in the service area of another radio base station, ie, other radio base It is also possible to consider the signal strength determination result indicating whether or not the frequency is free at the station.

That is, the logical product L ₁ (m) of the terminal determination result regarding the band m calculated by the equation (2) is transmitted to other radio base stations and simultaneously transmitted from other radio base stations in the vicinity. A free frequency band is determined by using Equation (3) further incorporating the logical product L _j (m) (j = 2, 3, 4) of the terminal determination result for band m into Equation (2). May be.

That is, the logical product L _j (m) transmitted from the neighboring wireless base stations 2, 3, and 4 existing in a circle with a radius of 5 km centered on the own wireless base station 1 is logical product L ₂ (m). , Logical product L ₃ (m), logical product L ₄ (m), the logical product L ₁ (m) of equation (2) is further transmitted from other radio base stations 2, 3, 4 in the vicinity. The logical product L ₁ ′ (m) obtained by logical product of the logical product L ₂ (m), the logical product L ₃ (m), and the logical product L ₄ (m) is obtained by the following equation (3).

L ₁ ′ (m) = L ₁ (m) · L ₂ (m) · L ₃ (m) · L ₄ (m)
= {D (1, m) · D (2, m) · D (3, m) ···
D (n, m)} L ₂ (m) L ₃ (m) L ₄ (m) (3) The band m in which the logical product L ₁ ′ (m) is “1” is This means that not only the radio base station 1 but also all nearby radio base stations (radio base stations 2, 3 and 4) are low-level signal strength bands whose signal strength is equal to or lower than a threshold value. In the vicinity of the radio base station 1, it can be determined more reliably that there is no radio wave of another radio communication system. Thus, such a band does not cause any interference and can be regarded as a free frequency band.

Here, the determination result transmitted from each wireless terminal existing in the service area of the wireless base station 1 is as shown in FIG. 16 described above, and all the nearby neighbors existing within a distance of 5 km from the wireless base station 1 are shown. If the logical products L ₂ (m), L ₃ (m), and L ₄ (m) transmitted from the other radio base stations 2, ₃ , and ₄ are the determination results as shown in FIG. The band logical product L ₁ ′ (m) (m = 1 to 10) is calculated as follows. FIG. 17 is a table showing power determination results for each band number in the other radio base stations 2, 3, and 4 adjacent to the radio base station 1 that has received the communication start request from the radio terminal 30A.

L ₁ ′ (1) = 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 1 = 0
L ₁ ′ (2) = 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 = 0
L ₁ ′ (3) = 0 · 1 · 0 · 0 · 0 · 1 · 0 · 0 · 0 · 0 · 0 = 0
L ₁ '(4) = 0 · 1 · 0 · 0 · 1 · 1 · 1 · 0 · 0 · 1 · 0 = 0
L ₁ '(5) = 1 · 0 · 0 · 1 · 0 · 1 · 1 · 1 · 1 · 1 · 1 = 0
L ₁ ′ (6) = 1 · 1 · 1 · 1 · 1 · 1 · 1 · 1 · 1 · 0 · 1 = 0
L ₁ ′ (7) = 1 · 1 · 1 · 1 · 1 · 1 · 1 · 1 · 1 · 1 · 1 = 1
L ₁ ′ (8) = 0 · 1 · 1 · 1 · 1 · 1 · 0 · 0 · 1 · 1 · 0 = 0
L ₁ ′ (9) = 1 · 1 · 1 · 1 · 0 · 1 · 1 · 1 · 0 · 1 · 0 = 0
L ₁ ′ (10) = 1 · 0 · 1 · 1 · 0 · 0 · 1 · 0 · 1 · 0 · 0 = 0
From the calculation result of the logical product as described above, the frequency determiner 10eA ₂ frequency bands determiner 10eA for communication of the wireless base station 1 is considered frequency band band number 7 is free. Accordingly, the wireless base station frequency determiner 10eA ₂ of communication frequency band determiner 10eA 1 having the structure of the wireless base station 10A of FIG. 12, the center frequency 2.465GHz band number 7, the bandwidth 10 MHz, the communication start It decides to use it for communication with the wireless terminal 30A that has transmitted the request packet, and sets the frequency and bandwidth of the wireless signal processing unit 10h shown in FIG. Further, as shown in the flowchart of FIG. 10, at the same time, the frequency instruction packet storing the frequency / bandwidth information determined to be used for communication of the radio terminal 30A is stored via the base station-terminal interface unit 10f. The communication start request packet is transmitted to the wireless terminal 30A that is the transmission source (step S14). The radio terminal 30A receives this frequency instruction packet (step S15), sets the frequency / bandwidth of the radio signal processing unit 30b shown in FIG. 11, and starts communication.

That is, the terminal measurement result of the signal strength of the radio signal measured by the radio wave detector 30e in each radio terminal 30A is compared with the determination threshold value, for example, −120 dBm, by the comparator 30f, or the terminal determination result of the signal strength obtained. , the result of the determination as a determination result of the signal strength at the radio base station the terminal determination result of the signal strength for each radio base station of each radio terminal by the determination result output unit of the logical product calculating unit 10eA ₁ of the radio base station, The inter-base station interface unit 10d transmits the signal to other nearby wireless communication station devices, while the terminal measurement result of the signal strength transmitted from the other wireless communication station device or the determination of the signal strength at the other wireless base station The result is received by the inter-base station interface unit 10d, and the frequency determinator 10e of the communication frequency band determinator 10e is received. By A _2, the radio base station 10A of the base station - the strength of the signal received by the terminal between the interface unit 10f terminal determination result or its own signal strength in the radio base station determination result with the other received by the base station between the interface unit 10d Based on the terminal determination result of the signal strength transmitted from the radio communication station device or the determination result of the signal strength at the other radio base station, it is an empty frequency where no radio signal exists around the radio base station 10A. To determine the frequency band of the radio signal used for communication with the radio terminal.

  Even if the radio terminal 30A is provided with the radio wave detector 30e and the comparator 30f that detect the vacant frequency as the terminal determination result of the signal strength by performing the operation as described above, Almost the same effect can be obtained.

That is, the radio base station 1 uses the terminal determination result of the signal strength of each band and the terminal determination result in one or more radio terminals existing in the radio base station 1 as the frequency band of the radio signal used for the current communication. Not only the obtained signal strength determination result in the radio base station 1 but also signals of each band in one or more radio terminals existing in other radio base stations 2, 3 and 4 located in the vicinity within a distance of 5 km, for example. Using the terminal determination result of the strength and the signal strength determination result in the other radio base stations 2, 3 and 4 obtained from the terminal determination result, it is possible to determine the free frequency in both the own and all other radio base stations. As a mechanism for deciding to use a band with a low signal strength below a predetermined threshold as the frequency band for communication this time, If radio wave is not weakened temporarily reception level, such as by blocking and fading due to obstructions from the wireless communication system, also, a band-pass filter 30e ₃ of the radio wave detector 30e, a part of the wireless terminal for detecting a free frequency Even if there is an error in the detection accuracy of the device, it is possible to reduce the probability of erroneous detection of empty frequencies around the radio base station 1 and increase the detection accuracy of empty frequencies.

  In this embodiment, the wireless base station 1 calculates the signal strength exchanged with other nearby wireless base stations 2, 3, 4 from the terminal determination result of the signal strength at each wireless terminal. However, the present invention is not limited to such a case, for example, as described above, for example, as described above centering on the exchange of signal strength determination results in each radio base station for each band. The terminal measurement result of the signal strength, which is the result of comparing the terminal measurement result of the signal strength measured at each wireless terminal with a determination threshold, for example, −120 dBm, is exchanged instead of the determination result of the signal strength at each wireless base station. Anyway. Alternatively, the terminal measurement result itself of the signal strength measured at each wireless terminal is received from each wireless terminal, and the terminal measurement result itself of the signal strength at each wireless terminal is received as the signal strength at each wireless base station. You may make it exchange instead of a determination result. In such a case, the determination means for comparing the terminal measurement result of the signal strength in the own radio base station and the terminal measurement result of the signal strength in the exchanged other radio base station with a predetermined threshold value for vacant frequency determination. A certain comparator may be installed on the radio base station side.

(Third embodiment)
Next, a third embodiment relating to a wireless communication system, a wireless communication station apparatus (wireless base station), a wireless terminal apparatus (wireless terminal), and a wireless communication method according to the present invention will be described. In the present embodiment, unlike the first embodiment, each radio base station uses a weight correction value corresponding to the distance between each radio base station in the communication frequency determination process on the radio base station side. This is a case where weighting correction is performed on the measurement result of the signal strength of the station.

  In this embodiment, the system configuration of the wireless communication system and the distance between the wireless base stations are the same as those in FIGS. 1 and 2, respectively. In addition, the configuration of the wireless terminal in this embodiment is the same as that of the first embodiment shown in FIG. As shown in FIG. 18, the configuration of the radio base station is the same as that of the radio base station 10 of FIG. 4 of the first embodiment except that the configuration of the communication frequency band determiner mounted on the radio base station is different. It is the same. FIG. 18 is a block configuration diagram showing an example of a block configuration of a radio base station in the third embodiment of the present invention. Each of the radio base stations 1, 2, 3, 4, and 5 in FIG. 1 has the same configuration as that in FIG. As described above, the radio base station 10B of FIG. 18 includes the communication frequency band determiner 10eB instead of the communication frequency band determiner 10e of the radio base station 10 shown in FIG. 4 as the first embodiment. The example of a structure which shows is shown.

An example of the configuration of the communication frequency band determiner 10eB in the present embodiment is shown in FIG. FIG. 19 is a block configuration diagram showing an example of the configuration of the communication frequency band determiner 10eB of the radio base station 10B shown in FIG. As shown in FIG. 19, the communication frequency band determiner 10eB, unlike the case of the communication frequency band determiner 10e shown in FIG. 6, the weight corrector 10eB _1, adder 10eB _2, comparator 10eB _3, frequency configured to determiner 10eB ₄ at least has been.

The weight corrector 10eB ₁ an adder 10eB _2, the measurement results of the signal strength at the other base stations transmitted from the measurement results of the signal strength and other wireless base station in the radio base station, the total frequency of utilization object for band, for each frequency band, there is provided a weight correcting means for performing weighting corrected by preset weight correction value, the weighting corrector 10eB ₁ is a radio signal transmitted from a radio wave detector 10c power ( Weighting coefficient obtained by weighting the measurement result of the signal strength) and the measurement result of the power (signal strength) of the radio signal transmitted from another radio base station according to the distance from the radio base station as a weight correction value performing correction for each band by, and outputs it to the adder 10eB _2. That is, the weight correction value applied here is determined according to the distance between the radio base stations.

Further, the adder 10eB ₂ adds the measurement results of the signal strengths of its own and other radio base stations weighted by the weight correction unit 10eB ₁ to the measurement results of the radio wave detector 10c and other radio base stations for each band. The correction signal intensity SP (m) (correction measurement result) is output.

Further, the comparator 10eB ₃ receives the signal strength measurement result of the own radio communication station apparatus and the other radio communication station apparatus that have been subjected to the weight correction by the weight corrector 10eB ₁ and the adder 10eB ₂ constituting the weight correction unit. A determination means for comparing the transmitted signal strength measurement result of another wireless communication station device with a predetermined threshold for determining a free frequency and outputting a signal strength determination result indicating whether the frequency is a free frequency is provided. The correction signal strength SP (m) obtained by adding the measurement results of the weighted signal strengths of the own and other wireless communication station devices is determined for each threshold and band that are determined in advance for determining the free frequency. A comparison result (determination result indicating whether or not the frequency is empty) is output. The frequency and bandwidth indicating a predetermined threshold value following a low signal level from the comparison result of the comparator 10eB ₃ can be extracted as a vacant frequency band.

Further, the frequency determiner 10eB ₄ is used by the wireless terminal 30 that is the transmission source of the communication start request packet for the current communication based on the comparison result output from the comparator 10eB ₃ (that is, the determination result of the empty frequency band). The frequency and bandwidth are determined and transmitted to the base station-terminal interface unit 10f as a frequency response signal in response to a frequency inquiry from the base station-terminal interface unit 10f. Further, the frequency and bandwidth used for the current communication are determined. It transmits to the radio signal processing unit 10h as a frequency instruction signal.

  In the following, with respect to the present embodiment using the radio terminal 30 and the radio base station 10B configured as shown in FIGS. 3 and 18, determination of the frequency and bandwidth of the radio signal used for communication in the radio base station 1 shown in FIG. Processing will be described with reference to the flowcharts of FIGS. 7 and 10 showing an example of the wireless communication method of the present invention. As described above, the configuration of the radio terminal includes the configuration of the radio terminal 30 as shown in FIG. 3, and as described above, the configuration of the radio base station 1 includes the radio base station 10B as shown in FIG. It shall consist of the following.

  In this embodiment, in the radio base station 1 of FIG. 1 having the configuration of the radio base station 10B, the signal strength of the radio signal is measured in order to detect the free frequency of the radio signal, as in the first embodiment. Two processes, a radio wave detection process to be performed and a communication start process to perform a series of processes from determination of a frequency band used for communication to the start of communication, are performed. The radio wave detection process is periodically executed at a predetermined cycle, and the communication start process is executed with a communication start request from a communication start request packet from a wireless terminal as a trigger.

  First, an example of radio wave detection processing in the present embodiment of the radio base station 1 having the configuration of the radio base station 10B in FIG. 18 will be described with reference to FIG. The radio wave detection process in the present embodiment of the radio base station 1 for detecting the free frequency of the radio signal is substantially the same as the flowchart of FIG. 7 in the first embodiment.

  In FIG. 7, first, a timer synchronized between all the radio base stations is set to time until a predetermined time period (step S1), and the timer reaches a predetermined time period (no in step S3). Then, the reduction process is performed (step S2), and when the timer expires (yes in step S3), the radio wave detection process is started.

When the radio wave detection process is started in the radio wave detector 10c shown in FIG. 5 provided in the radio base station 10B of FIG. 18, the radio wave detector 10c sets the frequency band 2.4 GHz-2.5 GHz of the candidate for use to 10 MHz. Separate the plurality of bands having a width of (10 bands in the present embodiment), the center frequency of the bandpass filter 10c ₃ is, between the 2.405GHz the center frequency of each band up to 2.495GHz, i.e. Until the measurement of the signal intensity in all frequency bands is completed (no in step S5), the center frequency is sequentially changed by 10 MHz (step S6), and each band of the radio signal received by the radio wave detection antenna 10b is measured. Is measured by the power measuring device 10c ₄ as the signal strength (step S4).

  When the measurement of the signal strength in all frequency bands is completed (yes in step S5), the signal strength measurement result is then transmitted to other radio base stations via the signal lines 21,..., 27 shown in FIG. Are exchanged (step S7). In the present embodiment in which the signal strength measurement result is weight-corrected according to the distance between the radio base stations, the radio base station exchanging the signal strength measurement result is different from the first embodiment in that it Not only radio base stations existing within a circle with a radius of 5 km centered on the base station, but all radio base stations existing in the vicinity (radio base stations 1, 2, 3, 4, 5 in this embodiment) Unlike the first embodiment, the information to be exchanged with other radio base stations is limited to the signal strength measurement result, and the measurement result is compared with a threshold value, for example, −120 dBm. There is no operation for exchanging judgment results.

  Here, in the radio base station 1, the measurement result of the signal strength of the radio base station 1 itself and the signal strength transmitted from each of the radio base stations 2, 3, 4 and 5 existing in the vicinity of the radio base station 1 The measurement results are assumed to be as shown in FIG. FIG. 20 shows measurement results of power, that is, signal strength, for each band number in each radio base station shown in FIG. 1 (radio base stations 1, 2, 3, 4, and 5 in this embodiment) in this embodiment. It is a table to show.

  The measurement result of the signal strength as shown in FIG. 20 is input to the communication frequency band determiner 10eB. In the communication frequency band determiner 10eB, based on the signal strength measurement results in the plurality of radio base stations of the own radio base station 1 and the other radio base stations 2, 3, 4 and 5, the surroundings of the radio base station 1 In this step, a free frequency band that is not currently used is extracted, and a free frequency band that is used for the current communication by the wireless terminal that is the transmission start request packet is determined.

  Next, in the present embodiment of the radio base station 1 having the configuration of the radio base station 10B of FIG. In this embodiment, the flowchart of the radio base station 1 that performs the communication start process of the radio terminal 30 is almost the same as that in FIG.

  First, the wireless terminal having the configuration of the wireless terminal 30 of FIG. 3 and requesting the start of communication sends a communication start request packet to the wireless base station of FIG. 18 via the base station-terminal interface unit 30d of FIG. It transmits with respect to the wireless base station 1 which consists of a structure of 10B (step S11). When the radio base station 1 receives the communication start request packet from the radio terminal 30 via the radio base station-terminal interface unit 10f in FIG. 18 (step S12), the radio frequency base station 10eB performs the radio communication. The determination process of the frequency band used by the terminal 30 for the current communication is performed according to the following procedure (step S13).

In communication frequency band determiner 10eB of radio base station 1 having the configuration of radio base station 10B in FIG. 18, first, in weight corrector 10eB ₁ shown in FIG. 19, the signal strength of each radio base station shown in FIG. The measurement result is multiplied by a weight coefficient as a weight correction value. Here, the weighting coefficient to be multiplied as the weight correction value is determined according to the distance between the radio base stations. For example, the weight w _o of the measurement result of the own radio base station and the measurement result of the signal strength are transmitted. Among the other radio base stations, the total number x of other radio base stations within a distance of 5 km from the own radio base station, the weight w _x of each measurement result of the other radio base station, and the distance from the own radio base station are When the total number y of other radio base stations exceeding 5 km and the weight w _y of each measurement result of the other radio base stations are set, it is determined according to the distance between the radio base stations as follows.

That is, the weighting factor w ₁ of the measurement result of the own radio base station is
w ₁ = w _o / z
Given in.

In addition, the weight coefficient w ₂ of the measurement result of each of the other radio base stations in the circle with a radius of 5 km centered on the own radio base station is
w ₂ = w _x / z
Given the weighting factor w ₃ of the other radio base stations each of the measurement results of outside circle of radius 5km centered on the current wireless base station is,
w ₃ = w _y / z
Given in.

Here, the variable z is
z = w _o + x · w _x + y · w _y
And is a normalization variable for normalizing the weighting factors w ₁ , w ₂ , and w ₃ .

For example, as the weight of the measurement result of the own radio base station and other radio base stations,
w _o = 1, w _x = 0.5, w _y = 0.25
In addition, as shown in FIG. 20, the total number of other radio base stations that have transmitted the signal strength measurement results to the radio base station 1 is four radio base stations 2, 3, 4, and 5. As shown in FIG. 2, among the four other radio base stations, there are three radio base stations whose distance from the radio base station 1 is within 5 km, that is, the radio base stations 2, 3, and 4, If the number of radio base stations exceeding 5 km is one of the radio base stations 5, the normalization variable z is
z = 1 + 3 × 0.5 + 1 × 0.25 = 2.75
Therefore, the weighting factor w ₁ of the measurement result of the radio base station is
w ₁ = 1 / 2.75
It is.

Further, the weight coefficient w ₂ of the measurement results of the radio base stations 2, 3, and 4 within a distance of 5 km is
w ₂ = 0.5 / 2.75
The weight coefficient w ₃ of the measurement result of the radio base station 5 exceeding the distance of 5 km is
w ₃ = 0.25 / 2.75
It is.

Therefore, in the weight corrector 10eB ₁ in the present embodiment in the case of the numerical example as described above, the weight coefficient w ₁ = 1 for the measurement results of the signal strength of each radio base station shown in FIG. /2.75, w ₂ = 0.5 / 2.75, and w ₃ = 0.25 / 2.75.

Then, added by the adder 10eB ₂ of communication frequency band determiner 10eB, for each band m, the measurement results of the signal strength of each radio base station which is weighted with the weighting factor _{w 1,} w 2, _{w 3} Then, the correction signal strength SP (m) subjected to the weight correction is calculated. That is, if the power measurement value (measurement result) of the band number m in the radio base station i (i = 1 to 5 in FIG. 20) is P _i (m), each radio base in the band m at the radio base station 1 The corrected signal strength SP ₁ (m) after weight-correcting and combining the signal strength measurement results P _i (m) of the stations is multiplied by a weight correction value, that is, a weighting factor corresponding to the distance between the radio base stations. As a result, it is given as follows.

SP ₁ (m) = (1 / 2.75) · P ₁ (m) + (0.5 / 2.75) · P ₂ (m)
+ (0.5 / 2.75) · P ₃ (m) + (0.5 / 2.75) · P ₄ (m)
+ (0.25 / 2.75) · P ₅ (m) (4)
Here, if the measurement results of the signal strength for each band in each of the radio base stations 1, 2, 3, 4 and 5 are as shown in FIG. 20, the radio base station shown in FIG. The calculation result of the correction signal intensity SP ₁ (m) for each band m in 1 is given as follows.

SP ₁ (1) = (1 / 2.75) · (−86)
+ (0.5 / 2.75) · (-95)
+ (0.5 / 2.75) · (−100)
+ (0.5 / 2.75) ・ (−97)
+ (0.25 / 2.75) · (−108)
= -94.2 dBm
SP ₁ (2) = − 99.3 dBm
SP ₁ (3) = − 116.0 dBm
SP ₁ (4) = -123.3 dBm
SP ₁ (5) = − 131.5 dBm
SP ₁ (6) = -121.9 dBm
SP ₁ (7) = -102.3 dBm
SP ₁ (8) = − 95.5 dBm
SP ₁ (9) = − 106.5 dBm
SP ₁ (10) = − 111.5 dBm
Next, in the comparator 10eB ₃ of the communication frequency band determiner 10eB, the corrected signal strength SP ₁ (m) after weight correction output from the adder 10eB ₂ is a predetermined threshold value for determining a free frequency, for example, −120 dBm. And a band below the threshold is determined to be empty. Therefore, when the correction signal intensity SP ₁ (m) of each band (each frequency band) as described above is obtained based on the measurement result of the signal intensity in FIG. 20, the frequency determiner 10eB ₄ performs the comparison. Based on the comparison result (determination result indicating whether or not the frequency is an empty frequency) from the device 10eB ₃ , the bands determined as the empty frequency band are the correction signal strengths SP ₁ (4), SP ₁ (5), and SP ₁ (6). Corresponding band numbers 4, 5, and 6 are considered to be vacant frequency bands. Further, among these three bands, it is determined that the band with the lowest correction signal intensity SP ₁ (m) (that is, the band number 5 in the above case) is the band with the least amount of interference, and Decide to use the frequency band for communication.

From the calculation results described above, in the frequency determiner 10eB ₄ frequency bands determiner 10eB for communication of the wireless base station 1, regarded as a frequency band is empty band number 5. Accordingly, the frequency determiner 10eB ₄ of the communication frequency band determiner 10eB of the radio base station 1 having the configuration of the radio base station 10B of FIG. 18 starts communication with a center frequency of 2.445 GHz and a bandwidth of 10 MHz of the band number 5. It decides to use for communication with the wireless terminal 30 that has transmitted the request packet, and sets the frequency and bandwidth of the wireless signal processing unit 10h shown in FIG. Further, as shown in the flowchart of FIG. 10, at the same time, the frequency instruction packet storing the frequency / bandwidth information determined to be used for communication of the wireless terminal 30 is stored via the base station-terminal interface unit 10f. The communication start request packet is transmitted to the wireless terminal 30 that is the transmission source (step S14). The wireless terminal 30 receives this frequency instruction packet (step S15), sets the frequency / bandwidth of the wireless signal processing unit 30b shown in FIG. 3, and starts communication.

As described above, as the communication frequency band determiner 10eB, the measurement results of the signal strength of the own radio base station 1 and the measurement results of the signal strengths transmitted from the other radio communication station devices 2, 3, 4, and 5 The weight corrector 10eB ₁ that performs weight correction for all frequency bands to be used by using a weight correction value (weight coefficient in this embodiment) set in advance according to the distance between the radio base stations for each frequency band. And the signal strength of the other radio communication station apparatus transmitted from the other radio communication station apparatus and the signal intensity measurement result of the own radio communication station apparatus that has been subjected to weight correction using the weight correction means comprising the adder 10eB ₂ Of the measured signal, that is, the correction signal strength SP ₁ (m) is compared with a predetermined threshold value for determining a free frequency, and indicates whether or not the frequency is a free frequency around the own radio communication station apparatus. A comparator 10eB ₃ for outputting a determination result of the strength by at least provided with, it possible to apply a weight correction of the measurement results of signal strength according to the distance from the radio base station 1, with, the radio communication It is possible to obtain a more accurate determination result of empty frequencies around the station apparatus.

To explain further, the radio base station 1 does not only perform the signal strength determination result in the radio base station 1 but also the weight correction according to the distance as the frequency band of the radio signal used for this communication. Using the signal strength determination results in all other radio base stations 2, 3, 4, and 5 located in the vicinity, including radio base stations that do not exist within a radius of 5 km from the radio base station 1,・ Every other radio base station adopts a mechanism that decides to use a band with a low signal strength below a predetermined threshold for vacant frequency determination as the frequency band for this communication. Therefore, for example, the reception level of radio waves from other radio communication systems is temporarily weakened due to shielding or fading by obstacles, or the radio wave detector 10c may be blocked. Such as de-pass filter 10c _3, as an error in the detection precision of an instrument portion of the radio base station for detecting a free frequency in some cases you are or occur, false detection of vacant frequency in one neighboring radio base station This can reduce the probability of causing vacancy and increase the detection accuracy of vacant frequencies.

  In the above-described embodiment, the signal strength measurement result in the own radio communication station device and the signal strength measurement result in the other radio communication station device transmitted from the other radio communication station device are all used. Although an example of performing weight correction by using a weight correction value to which a weighting factor set in advance according to the distance between radio base stations is described for each frequency band has been described, the present invention is not limited to such a case. Absent. For example, weight correction is performed on the terminal measurement result of the signal strength measured in one or a plurality of radio terminals existing in the service area of the own radio base station and the terminal measurement result of the signal strength of another radio base station. Alternatively, from the addition average value obtained by averaging the terminal measurement results of the signal strength transmitted from one or more of the wireless terminals existing in the service area of the own wireless base station and from other wireless base stations You may make it perform weight correction with respect to the said addition average value transmitted.

(Fourth embodiment)
Next, a fourth embodiment relating to a wireless communication system, a wireless communication station device (wireless base station), a wireless terminal device (wireless terminal), and a wireless communication method according to the present invention will be described. In this embodiment, in the frequency determination process for communication on the radio base station side, weight correction is performed on the signal strength measurement result of each radio base station using a weight correction value corresponding to the distance to other radio base stations. An example different from the third example will be described as an example of applying the above. That is, in this embodiment, the weight correction value corresponding to the distance between the radio base stations is determined as a loss amount generated in proportion to the distance instead of multiplying the weight coefficient as in the third embodiment. This is a case where weighting is performed according to the amount of propagation loss. In the following description, it is assumed that radio waves of other radio communication systems are transmitted and received at a position that is at least equal to the distance between the radio base stations and other radio base stations. A case where the amount of propagation loss determined according to the distance between the two is simply added to the measurement result of the signal strength will be described as an example. The propagation loss amount may be added as a vector.

  In this embodiment, the system configuration of the wireless communication system and the distance between the wireless base stations are the same as those in FIGS. 1 and 2, respectively. The configuration of the wireless terminal in this embodiment is the same as that of FIG. 3 of the first embodiment, but the configuration of the wireless base station is for communication mounted in the wireless base station as shown in FIG. The configuration is the same as that of the radio base station 10 of FIG. 4 in the first embodiment except that the configuration of the frequency band determiner is different. FIG. 21 is a block configuration diagram illustrating an example of a block configuration of a radio base station according to the fourth embodiment of the present invention. Each of the radio base stations 1, 2, 3, 4, and 5 in FIG. 1 has the same configuration as that in FIG. As described above, the radio base station 10C in FIG. 21 includes the communication frequency band determiner 10eC instead of the communication frequency band determiner 10e of the radio base station 10 shown in FIG. 4 as the first embodiment. The example of a structure which shows is shown.

An example of the configuration of the communication frequency band determiner 10eC in the present embodiment is shown in FIG. FIG. 22 is a block configuration diagram showing an example of the configuration of the communication frequency band determiner 10eC of the radio base station 10C shown in FIG. As shown in FIG. 22, the communication frequency band determiner 10eC is different from the communication frequency band determiner 10e shown in FIG. 6, and includes a weight corrector 10eC ₁ , a comparator 10eC ₂ , an AND operator 10eC ₃ determiner 10EC _4, it is constituted by at least has, as in the third embodiment, the communication frequency band determiner 10EC, is intended to enter the signal strength from the other radio base station The comparison result between the measurement result and the threshold value (determination result indicating whether or not the frequency is empty) is not input.

Here, the weight corrector 10EC ₁ of communication frequency band determiner 10EC in this embodiment, the signal strength at the other base stations transmitted from the measurement results of the signal strength at the radio base station and the other radio base station The measurement result is provided for weight correction means for performing weight correction for each frequency band using a weight correction value set in advance for all frequency bands to be used, and wireless signals transmitted from other wireless base stations are provided. The measurement result of the signal power, that is, the signal strength, is output as a corrected signal strength corrected for each band in a form weighted by the amount of propagation loss generated according to the distance from the own radio base station.

Further, the comparator 10EC ₂ were weight correction than the weight corrector 10EC ₁ constituting the weight correction means, the other wireless communication transmitted from the measurement result of the signal strength of the radio communication station and another wireless communication station Comparing the measurement result of the signal strength of the station device with a predetermined threshold value for determining a free frequency, and providing a determination means for outputting a determination result of the signal strength indicating whether or not it is a free frequency, a weight a correction signal intensities corrected by the corrector 10EC _1, and outputs comparison compared with a predetermined threshold value for example -120dBm results for the available frequency determined (determination result indicating whether the available frequency) for each band. The frequency and bandwidth indicating a predetermined threshold value following a low signal level from the comparison result of the comparator 10EC ₂ can be extracted as a vacant frequency band.

Note that the AND operator 10eC ₃ and the frequency determiner 10eC ₄ in the communication frequency band determiner 10eC in FIG. 22 are the AND operator 10e ₂ in the communication frequency band determiner 10e in FIG. 6 of the first embodiment. The frequency determiner 10e ₃ is exactly the same.

Further, if the weight corrector 10eB ₁ of communication frequency band determiner 10eB of FIG. 19 in the third embodiment, the measurement result and which has been transmitted from the measurement results and other radio base station of the radio base station in contrast, although a weighting factor corresponding to the distance was to multiply the weight corrector 10EC ₁ of communication frequency band determiner 10EC in this embodiment, as described above, the radio signals of its own radio base station A correction that adds the amount of propagation loss that occurs according to the distance from the radio base station to the power measurement result and the power measurement result of the radio signal transmitted from another radio base station. It is.

  Hereinafter, with respect to the present embodiment using the radio terminal 30 and the radio base station 10C configured as shown in FIGS. 3 and 21, the frequency and bandwidth of the radio signal used for communication in the radio base station 1 shown in FIG. 1 are determined. Processing will be described with reference to the flowcharts of FIGS. 7 and 10 showing an example of the wireless communication method of the present invention. As described above, the configuration of the radio terminal includes the configuration of the radio terminal 30 as shown in FIG. 3, and the configuration of the radio base station 1 as described above includes the radio base station 10C as shown in FIG. It shall consist of the following.

  In the present embodiment, in the radio base station 1 of FIG. 1 having the configuration of the radio base station 10C of FIG. 21, the signal of the radio signal is detected in order to detect the free frequency of the radio signal, as in the first embodiment. Two processes are performed: a radio wave detection process for measuring the intensity and a communication start process for performing a series of processes from the determination of the frequency band used for communication to the start of communication. The radio wave detection process is periodically executed at a predetermined cycle, and the communication start process is executed with a communication start request from a communication start request packet from a wireless terminal as a trigger.

  First, an example of radio wave detection processing in the present embodiment of the radio base station 1 having the configuration of the radio base station 10C of FIG. 21 will be described with reference to FIG. The radio wave detection process in the present embodiment of the radio base station 1 for detecting the free frequency of the radio signal is substantially the same as the flowchart of FIG. 7 in the first embodiment.

  In FIG. 7, first, a timer synchronized between all the radio base stations is set to time until a predetermined time period (step S1), and the timer reaches a predetermined time period (no in step S3). Then, the reduction process is performed (step S2), and when the timer expires (yes in step S3), the radio wave detection process is started.

When the radio wave detector 10c shown in FIG. 5 provided in the radio base station 10C of FIG. 21 starts radio wave detection processing, the radio wave detector 10c sets the frequency band 2.4 GHz-2.5 GHz of the candidate for use to 10 MHz. Separate the plurality of bands having a width of (10 bands in the present embodiment), the center frequency of the bandpass filter 10c ₃ is, between the 2.405GHz the center frequency of each band up to 2.495GHz, i.e. Until the measurement of the signal intensity in all frequency bands is completed (no in step S5), the center frequency is sequentially changed by 10 MHz (step S6), and each band of the radio signal received by the radio wave detection antenna 10b is measured. Is measured by the power measuring device 10c ₄ as the signal strength (step S4).

  When the measurement of the signal strength in all frequency bands is completed (yes in step S5), the signal strength measurement result is then transmitted to other radio base stations via the signal lines 21,..., 27 shown in FIG. Are exchanged (step S7). In the present embodiment in which the signal strength measurement result is weight-corrected according to the distance between the radio base stations, the radio base station exchanging the signal strength measurement result is different from the first embodiment in that it Not only radio base stations existing within a circle with a radius of 5 km centered on the base station, but all radio base stations existing in the vicinity (radio base stations 1, 2, 3, 4, 5 in this embodiment) Unlike the first embodiment, the information to be exchanged with other radio base stations is the measurement result of the signal strength, and the determination is made by comparing the measurement result with a threshold value, for example, −120 dBm. No action to exchange results.

  Here, in the radio base station 1, the measurement result of the signal strength of the radio base station 1 itself and the signal strength transmitted from each of the radio base stations 2, 3, 4 and 5 existing in the vicinity of the radio base station 1 The measurement results are as shown in FIG. FIG. 23 shows measurement results of power, ie, signal strength, for each band number in each radio base station shown in FIG. 1 (in the case of FIG. 23, radio base stations 1, 2, 3, 4, and 5) in this embodiment. It is a table.

The measurement result of the signal strength as shown in FIG. 23 is input to the communication frequency band determiner 10eC. Note that the signal strength of the wireless base station 1 itself, because the propagation loss amount of the correction processing based on the distance between the own radio base station 1 is unnecessary, and enter the measurement results directly into the comparator 10EC ₂ The threshold value, for example, −120 dBm may be compared, but the weight correction unit 10 eC ₁ of the communication frequency band determiner 10 eC in FIG. The case where the measurement result from the container 10c is input is illustrated.

  The measurement result of the signal strength as shown in FIG. 23 is input to the communication frequency band determiner 10eC. In the communication frequency band determiner 10eC, based on the signal strength measurement results in the plurality of radio base stations of the own radio base station 1 and the other radio base stations 2, 3, 4 and 5, the periphery of the radio base station 1 In this step, a free frequency band that is not currently used is extracted, and a free frequency band that the wireless terminal uses for the current communication is determined.

  Next, in the present embodiment of the radio base station 1 having the configuration of the radio base station 10C of FIG. In this embodiment, the flowchart of the radio base station 1 that performs the communication start process of the radio terminal 30 is almost the same as that in FIG.

  First, the wireless terminal 30 having the configuration of the wireless terminal 30 in FIG. 3 and requesting the start of communication sends a communication start request packet to the wireless base station in FIG. 21 via the base station-terminal interface unit 30d in FIG. It transmits to the radio base station 1 having the configuration of the station 10C (step S11). When the radio base station 1 receives a communication start request packet from the radio terminal 30 via the radio base station-terminal interface unit 10f of FIG. 21 (step S12), the radio frequency base station 10eC performs the radio communication. The determination process of the frequency band used by the terminal 30 for the current communication is performed according to the following procedure (step S13).

In the communication frequency band determiner 10eC of the radio base station 1 having the configuration of the radio base station 10C in FIG. 21, first, in the weight corrector 10eC ₁ shown in FIG. The amount of propagation loss corresponding to the distance from the radio base station 1 to the measurement result of the signal strength transmitted from the radio base station (radio base stations 2, 3, 4, 5 shown in FIG. 23) Is further added. Note that the measurement result of the signal strength of the own radio base station 1 is output as it is because no propagation loss amount to be added as a weight correction value is generated.

Here, it is assumed that the propagation loss amount added as a weight correction value for the measurement result of the signal strength transmitted from the other radio base station follows the s power law of the distance from the own radio base station 1, and the other radio base station If the distance between i (i = 2, 3, 4, 5) and the own radio base station 1 is R (i), the amount of propagation loss to be further added to the signal strength measurement result of the other radio base station L (i) is approximately
L (i) = − 10 × s × log ₁₀ R (i) [dB]
As given. By adding the propagation loss amount L (i) thus determined to the respective signal strength measurement results of the radio base stations 2, 3, 4 and 5 transmitted to the radio base station 1, respectively. It is possible to obtain the correction signal intensity whose weight is corrected by the weight correction value corresponding to the distance.

  Here, the distance between the radio base station 1 and the other radio base stations 2, 3, 4, and 5 is as shown in FIG. 2, and for example, s that defines the s power law of the distance is s. Assuming that = 3.0, the propagation loss amounts L (i) giving the weight correction values for the measurement results of the radio base stations 2, 3, 4, and 5 are as follows.

That is, the propagation loss L (2) that gives a correction amount for the measurement result of the radio base station 2 is
L (2) = − 10 × 3.0 × log ₁₀ 3 = −14 [dB]
The propagation loss amount L (3) that gives a correction amount for the measurement result of the radio base station 3 is
L (3) = − 10 × 3.0 × log ₁₀ 4 = −18 [dB]
It is.

Further, a propagation loss amount L (4) that gives a correction amount for the measurement result of the wireless base station 4 is:
L (4) = − 10 × 3.0 × log ₁₀ 2 = −9 [dB]
The propagation loss amount L (5) that gives a correction amount for the measurement result of the radio base station 5 is
L (5) = − 10 × 3.0 × log ₁₀ 6 = −23 [dB]
It is.

  Therefore, the measurement results of the radio base stations 2, 3, 4, and 5 shown in FIG. 23 are further added with propagation loss amounts −14 dBm, −18 dBm, −9 dBm, and −23 dBm that give the respective weight correction values. The correction measurement result as shown in the correction value column in FIG. Note that the measurement result after the weight correction of the own radio base station 1, that is, the correction signal strength, is exactly the same value as in FIG. FIG. 24 is a table showing a corrected measurement result (corrected signal strength) obtained by correcting the measurement result of power for each band number in each radio base station shown in FIG. 1 and a determination result in this embodiment.

Then, in the comparator 10EC ₂ of communication frequency band determiner 10EC, the correction signal after weight correction due to propagation loss measurement results of the weight corrector 10EC radio base station 2, 3, 4, 5 output from the ₁ The intensity is compared with a predetermined threshold value for vacant frequency determination, for example, -120 dBm, and a band below the threshold value is determined to be vacant. Therefore, the comparison with the threshold value for example -120 dBm, the determination result of the wireless base station 1, 2, 3, 4 each of the signal intensities output from the comparator 10EC ₂ shows the comparison column for a threshold of 24 It becomes like this. Here, the frequency band (vacant) in which the band displayed as “vacant” in the comparison column with the threshold value in FIG. 24 has a low signal strength of a threshold value, for example, −120 dBm or less as the signal strength after weight correction (corrected signal strength). Frequency band).

Thereafter, the logical product operation unit 10EC ₃ of the communication frequency band determiner 10EC, Telecommunications detector 10c of the radio base station 1 that is input from the determination result comparator 10EC all radio base stations that is output from the ₂ For each of the determination results 1, 2, 3, 4, and 5 (determination result indicating whether or not the frequency is free), the logical product L ₁ for each band m is the same as the logical product operator 10e ₂ in the first embodiment. Find (m). Note that, as a determination result of the band m in the radio base station i (i = 1 to 5), if it is determined that the band is an empty frequency band, the determination result D (i, m) = 1 is determined to be an empty frequency band. Otherwise, assuming that the determination result D (i, m) = 0, the band m in which the logical product L ₁ (m) is “1” is a radio wave of another wireless communication system around the wireless base station 1. Since there is no interference, no interference occurs and it can be regarded as an empty frequency band.

Here, assuming that the correction signal intensity for each band in each of the radio base stations 1, 2, 3, 4, and 5 is a determination result as shown in FIG. 24, the logical product L ₁ (m) for each band m is The calculation result is given as follows.

L ₁ (1) = D (1,1) · D (2,1) · D (3,1)
・ D (4,1) ・ D (5,1)
= 0 ・ 1 ・ 1 ・ 0 ・ 1 = 0
L ₁ (2) = 0 · 1 · 0 · 0 · 1 = 0
L ₁ (3) = 0 · 1 · 0 · 1 · 0 = 0
L ₁ (4) = 1 · 0 · 0 · 0 · 1 = 0
L ₁ (5) = 1 · 1 · 1 · 1 · 1 = 1
L ₁ (6) = 0 · 1 · 1 · 1 · 1 = 0
L ₁ (7) = 0 · 0 · 1 · 1 · 1 = 0
L ₁ (8) = 0, 0, 0, 0, 1 = 0
L ₁ (9) = 0 · 0 · 1 · 0 · 0 = 0
L ₁ (10) = 0 · 0 · 1 · 0 · 0 = 0
The band m in which the logical product L ₁ (m) is “1” includes not only the own radio base station 1 but also all other radio base stations 2, 3, 4, and 5 in the vicinity. This means that the corrected signal strength after performing weight correction in consideration of the amount of propagation loss corresponding to it is a low level signal strength of a predetermined threshold value, for example, −120 dBm or less. Thus, it can be more reliably determined that there is no radio wave of another wireless communication system.

From the calculation results described above, in the frequency determiner 10EC ₄ frequency bands determiner 10EC for communication of the wireless base station 1, regarded as a frequency band is empty band number 5. Therefore, the frequency determiner 10eC ₄ of the communication frequency band determiner 10eC of the radio base station 1 having the configuration of the radio base station 10C of FIG. It decides to use for communication with the wireless terminal 30 that has transmitted the request packet, and sets the frequency / bandwidth of the wireless signal processing unit 10h shown in FIG. Further, as shown in the flowchart of FIG. 10, at the same time, the frequency instruction packet storing the frequency / bandwidth information determined to be used for communication of the wireless terminal 30 is stored via the base station-terminal interface unit 10f. The communication start request packet is transmitted to the wireless terminal 30 that is the transmission source (step S14). The wireless terminal 30 receives this frequency instruction packet (step S15), sets the frequency / bandwidth of the wireless signal processing unit 30b shown in FIG. 3, and starts communication.

As described above, as the communication frequency band determiner 10eC, the measurement results of the signal strength of the own radio base station 1 and the measurement results of the respective signal strengths transmitted from the other radio communication station devices 2, 3, 4, and 5 The weight corrector 10eC that performs weight correction for all frequency bands to be used by using a weight correction value (propagation loss amount in this embodiment) set in advance according to the distance between the radio base stations for each frequency band. _The signal strength measurement result of the own radio communication station apparatus and the signal intensity measurement result of the other radio communication station apparatus transmitted from the other radio communication station apparatus, that is, the correction corrected by the weight correction means consisting of ₁ Comparator 1 that compares the signal strength with a predetermined threshold value for vacant frequency determination and outputs a signal strength determination result indicating whether or not the frequency is a vacant frequency around the own radio communication station apparatus. 0eC ₂ makes it possible to perform weight correction of the measurement result of the signal strength in accordance with the distance from the own radio base station 1, and thus more accurate idle frequency around the own radio communication station apparatus. The determination result can be obtained.

To explain further, the radio base station 1 does not only perform the signal strength determination result in the radio base station 1 but also the weight correction according to the distance as the frequency band of the radio signal used for this communication. Using the signal strength determination results in all other radio base stations 2, 3, 4, and 5 located in the vicinity, including radio base stations that do not exist within a radius of 5 km from the radio base station 1,・ Every other radio base station adopts a mechanism that decides to use a band with a low signal strength below a predetermined threshold for vacant frequency determination as the frequency band for this communication. Therefore, for example, the reception level of radio waves from other radio communication systems is temporarily weakened due to shielding or fading by obstacles, or the radio wave detector 10c may be blocked. Such as de-pass filter 10c _3, as an error in the detection precision of an instrument portion of the radio base station for detecting a free frequency in some cases you are or occur, false detection of vacant frequency in one neighboring radio base station This can reduce the probability of causing vacancy and increase the detection accuracy of vacant frequencies.

  In the above-described embodiment, the signal strength measurement result in the own radio communication station device and the signal strength measurement result in the other radio communication station device transmitted from the other radio communication station device are all used. Although an example of performing weight correction by using a weight correction value applying a propagation loss amount set in advance according to the distance between radio base stations for each frequency band has been described, the present invention is limited to such a case. is not. For example, weight correction is performed on the terminal measurement result of the signal strength measured in one or a plurality of radio terminals existing in the service area of the own radio base station and the terminal measurement result of the signal strength of another radio base station. Alternatively, from the addition average value obtained by averaging the terminal measurement results of the signal strength transmitted from one or more of the wireless terminals existing in the service area of the own wireless base station and from other wireless base stations You may make it perform weight correction with respect to the said addition average value transmitted.

  Further, in the present embodiment, the case where the propagation loss amount determined according to the distance is added to the measurement result of the signal intensity from the other radio base stations 2, 3, 4, and 5 is shown. When the base stations 2, 3, 4, and 5 measure the signal strength of each band, they also acquire information indicating the direction in which the radio waves of that signal strength were received (information indicating the direction of presence of the radio wave transmission source). Then, when transmitting the measurement result of the signal strength from each of the other radio base stations 2, 3, 4 and 5, information regarding the reception direction may be added and transmitted. In such a case, when the signal strength measurement result is corrected using the propagation delay amount, it is also possible to perform vector calculation using information related to the reception direction to perform weight correction of the signal strength measurement result. .

(Fifth embodiment)
Next, a fifth embodiment relating to a wireless communication system, a wireless communication station apparatus (wireless base station), a wireless terminal apparatus (wireless terminal), and a wireless communication method according to the present invention will be described. In this embodiment, unlike the second embodiment, only signal strength is measured as radio wave detection processing performed on the wireless terminal side, and signal strength obtained from one or more wireless terminals existing in the service area is obtained. This shows a case where the comparison processing of the addition average value obtained by averaging the measurement results and the threshold value is performed on the radio base station side.

  In this embodiment, the system configuration of the wireless communication system and the distance between the wireless base stations are the same as those in FIGS. 1 and 2, respectively. Further, FIG. 25 shows the configuration of the wireless terminal in this embodiment. FIG. 25 is a block diagram showing an example of a block configuration of a wireless terminal in the fifth embodiment of the present invention, except that the comparator 30 is deleted from the wireless terminal 30A shown in FIG. 11 as the second embodiment. An example having exactly the same configuration as the wireless terminal 30A is shown.

  In radio terminal 30D of FIG. 25, switch 1 30c is connected to the A side during radio wave detection processing and communication start processing, similarly to radio terminal 30A of FIG. 11, and radio signal processing unit 30b is a base station-terminal interface. The wireless signal processing unit 30b is connected to an upper layer processing unit (not shown). On the other hand, the switch 2 30g is connected to the C side during the radio wave detection process, and the antenna 30a is connected to the radio wave detector 30e during the radio wave detection process, and is connected to the D side during the communication start process and normal communication. The antenna 30a is connected to the radio signal processing unit 30b.

  In addition, the radio wave detector 30e, like the radio terminal 30A in FIG. 11, measures the signal strength of the radio signal existing around the radio terminal 30D in the entire frequency band to be used as a terminal measurement result of the signal strength. The base station-terminal interface unit 30d provides measurement means, and the terminal side transmission / reception means for transmitting / receiving information to / from the wireless base station in the service area in which the wireless terminal 30D exists, as in the wireless terminal 30A of FIG. Is to provide. During the radio wave detection process, the terminal measurement result of the signal intensity measured by the radio wave detector 30e is transmitted to the radio base station 10D in the service area where the radio terminal 30D exists by the base station-terminal interface unit 30d.

  Next, FIG. 26 shows an example of the configuration of the radio base station in the present embodiment. FIG. 26 is a block configuration diagram illustrating an example of a block configuration of a radio base station according to the fifth embodiment of the present invention. Each of the radio base stations 1, 2, 3, 4, and 5 in FIG. 1 has the same configuration as that in FIG. The radio base station 10D shown in FIG. 26 is the same as the radio base station 10A of FIG. 12 except that the configuration of the communication frequency band determiner mounted on the radio base station is different. That is, as described above, the radio base station 10D of FIG. 26 replaces the communication frequency band determiner 10eA of the radio base station 10A shown in FIG. 12 as the second embodiment with a communication frequency band determiner 10eD. An example of the installed configuration is shown.

  The base station-terminal interface unit 10f in the radio base station 10D in FIG. 26 is the station device side that transmits and receives information to and from the radio terminal 30D that exists in the service area of the radio base station 10D, as in the radio base station 10A in FIG. The communication frequency band determiner 10eD provides a transmission / reception means, and the communication frequency band determiner 10eD, as in the case of the communication frequency band determiner 10eA of the radio base station 10A of FIG. The inter-base station interface unit 10d provides communication means for transmitting / receiving information to / from each other between a plurality of radio communication station apparatuses, similar to the radio base station 10A of FIG. It is to provide.

FIG. 27 shows an example of the configuration of the communication frequency band determiner 10eD installed in the radio base station 10D of FIG. FIG. 27 is a block configuration diagram showing an example of the configuration of the communication frequency band determiner 10eD of the radio base station 10D shown in FIG. As shown in FIG. 27, the communication frequency band determiner 10eD is configured to include at least an average calculator 10eD ₁ , a comparator 10eD ₂ , and a frequency determiner 10eD ₃ .

  In the present embodiment, the own radio base station 10D does not include the radio wave detector 10c, so that the power of the radio signal, that is, the signal strength is not detected on the own radio base station 10D side, and the own radio base station 10D The terminal measurement result of the detected signal strength detected on the wireless terminal side having a configuration like the wireless terminal 30D in FIG. 25 existing in the service area and information on the wireless terminal 30D existing in the service area of the wireless base station 10D and information Is input from the base station-terminal interface unit 10f, which is a station apparatus side transmitting / receiving means for transmitting / receiving.

Therefore, the average computing unit 10eD ₁ uses the terminal measurement result of the signal strength transmitted from one or more radio terminals 30D existing in the service area of the radio base station 10D for all frequency bands to be used. It provides an average calculation means for calculating an addition average value A (m) corresponding to the measurement result of the signal strength in the own radio base station 10D by averaging for each band, and an interface between base stations The calculated addition average value A (m) is transmitted to other radio base stations existing in the vicinity via the unit 10d, while the addition average value A (m) transmitted from the other radio base station is transmitted. A total addition average value A ′ (m) is calculated as a result of further receiving and averaging the addition average value A (m) of the own radio base station and other radio base stations.

In some cases, information exchanged with other radio base stations may be the terminal measurement result itself of the signal strength received from each radio terminal 30D instead of the addition average value. In such a case, the average calculator 10ED ₁ is a terminal measurement results of the power or signal strength of a radio signal which has been transmitted from the wireless terminal 30D which are present in the service area of the radio base station 10D, base station - terminal While being input via the inter-interface unit 10f and transmitted to other radio base stations, the terminal measurement result of the power of the radio signal transmitted from the other radio base station, that is, the signal strength, is transmitted to the inter-base station interface unit 10d. The total addition average value A ′ (m) obtained by adding the respective measurement results for each band m and averaging them is calculated. The terminal measurements of the signal strength from the wireless terminal 30D, the base station through the frequency determiner 10eD ₃ - is periodically inputted from a terminal between the interface unit 10f, the terminal measurement results from another wireless base station, It is periodically input from the inter-base station interface unit 10d.

Comparator 10ED ₂ has an average calculator the average value was calculated by 10eD ₁ A (m) and another wireless communication station the average value A which has been transmitted from the (m), averaged further sum Is compared with a predetermined threshold value for vacant frequency determination, and a determination means for outputting a signal strength determination result indicating whether or not the frequency is vacant is provided. first, the average calculator 10eD total average value a of each terminal measurement results calculated in ₁ '(m), comparison was compared with a predetermined threshold value for example -120dBm for the determination of the available frequency results (or free frequency not Is output for each band m. And Thus, it is possible to from the comparison result in the comparator 10ED _2, extracts the frequency and bandwidth indicating a predetermined threshold value below low signal levels as free frequency band L "(m).

Further, the frequency determiner 10eD ₃ uses the comparison result output from the comparator 10eD _2, that is, the vacant frequency band L ″ (m), by the wireless terminal 30D that is the transmission source of the communication start request packet for the current communication. The frequency and bandwidth are determined and transmitted to the base station-terminal interface unit 10f as a frequency response signal in response to a frequency inquiry from the base station-terminal interface unit 10f. Further, the frequency and bandwidth used for the current communication are determined. The frequency determiner 10eD ₃ transmits the measurement result received from the wireless terminal by the base station-terminal interface unit 10f as described above between the base station and the terminal. also it has a function of relaying the average calculator 10ED ₁ from the interface unit 10f.

  Hereinafter, with respect to the present embodiment using the radio terminal 30D and the radio base station 10D configured as shown in FIG. 25 and FIG. 26, the determination of the frequency and bandwidth of the radio signal used for communication in the radio base station 1 shown in FIG. Processing will be described with reference to the flowcharts of FIGS. 28 and 10 showing an example of the wireless communication method of the present invention. As described above, the configuration of the radio terminal includes the configuration of the radio terminal 30D as illustrated in FIG. 25. As described above, the configuration of the radio base station 1 includes the radio base station 10D as illustrated in FIG. It shall consist of the following.

  In the present embodiment, in the radio terminal 30D, radio wave detection processing for measuring the signal strength of the radio signal is performed in order to detect a vacant frequency of the radio signal. In the radio base station 1 having the configuration of the radio base station 10D, A communication start process for performing a series of processes from determination of a frequency band used for communication to the start of communication is performed. The radio wave detection process in the radio terminal 30D is periodically executed at a predetermined cycle, and the communication start process in the radio base station 1 is triggered by a communication start request by a communication start request packet from the radio terminal. Is done.

  First, an example of radio wave detection processing in the present embodiment of the wireless terminal 30D for detecting a vacant frequency of a wireless signal will be described with reference to FIG. FIG. 28 is a flowchart showing an example of radio wave detection processing in each wireless terminal according to the fifth embodiment of the present invention. The radio wave detection processing in the wireless terminal 30A described in the flowchart of FIG. 14 in the second embodiment; Almost the same processing is performed on the wireless terminal 30D side except that the operation of comparing the terminal measurement result of the signal strength with the determination threshold is deleted.

In FIG. 28, first, it is set to time until a predetermined time period using a timer synchronized with the wireless base station 1 in the service area where the wireless terminal 30D exists (step S31). Until the timer reaches a predetermined time limit (no in step S33), a decrease process is performed at a timing synchronized with the radio base station 1 (step S32). When the timer expires (yes in step S33), The radio wave detection process is started. Here, the timer is for synchronization among all base stations have been taken, the center frequency of the bandpass filter 10c ₃ shown in FIG. 5 in the wave detector 30e provided in the radio terminal 30D side Can be arbitrarily set in the 2.4 GHz-2.5 GHz band, and the bandwidth is assumed to be 10 MHz.

When the radio wave detection process in the radio wave detector 30e is started, the radio wave detector 30e uses a plurality of bands (10 in the present embodiment) having a frequency band of 2.4 GHz-2.5 GHz as candidates for use and having a width of 10 MHz. until delimiting the band), the center frequency of the bandpass filter 10c ₃ is, between the 2.405GHz the center frequency of each band up to 2.495GHz, i.e., to complete the measurement of the signal strength of the entire frequency band (No in step S35) The center frequency is sequentially changed by 10 MHz (step S36), and the power measurement shown in FIG. 5 in the radio wave detector 30e is performed using the power of each band as the signal strength for the radio signal received by the antenna 30a. Measurement is performed by the instrument 10c ₄ (step S34).

  When the measurement of the signal strength is completed over the entire frequency band (yes in step S35), the terminal measurement result of the signal strength in the entire frequency band is edited into the measurement result notification packet in the base station-terminal interface unit 30d. Is transmitted to the radio base station 1 (step S37). The wireless base station 1 that has received the measurement result notification packet periodically transmitted from each wireless terminal in the service area at a predetermined cycle by the base station-terminal interface unit 10f is included in the measurement result notification packet. The terminal measurement result of the signal strength at the wireless terminal is transmitted to the communication frequency band determiner 10eD.

  Here, in the case where the number of wireless terminals existing in the service area of the own wireless base station 10D (in this embodiment, the wireless base station 1) is eight terminals 1 to 8, the radio wave detector of each wireless terminal It is assumed that the terminal measurement result at 30e is as shown in FIG. 15 described above as the second embodiment.

  Next, in the present embodiment of the radio base station 1 having the configuration of the radio base station 10D of FIG. In this embodiment, the operation of the radio base station 1 that performs the communication start process of the radio terminal 30D is almost the same as the flowchart of FIG. 10 shown as the first embodiment, but the radio base station 10D itself has the operation as shown in FIG. The radio wave detector 10c is not provided, and the terminal measurement result of the signal strength is transmitted from the wireless terminal.

  First, the wireless terminal having the configuration of the wireless terminal 30D in FIG. 25 and requesting the start of communication transmits the communication start request packet to the wireless base station in FIG. 26 via the base station-terminal interface unit 30d in FIG. It transmits with respect to the wireless base station 1 which consists of a 10D structure (step S11). When the radio base station 1 receives the communication start request packet from the radio terminal 30D via the radio base station-terminal interface unit 10f in FIG. 26 (step S12), the radio frequency station determiner 10eD performs the radio communication. The determination process of the frequency band used by the terminal 30D for the current communication is performed according to the following procedure (step S13).

In the communication frequency band determiner 10eD of the radio base station 1 having the configuration of the radio base station 10D of FIG. receives the results, we obtain the average value a (m) of the measurement results of the radio terminal in the average calculator 10ED ₁ in Figure 27.

In general, for a case where there are a total of n radio terminals in the service area of the own radio base station 1, the terminal measurement result of the band m in the radio terminal 1 is I (1, m), and the band in the radio terminal 2 is The terminal measurement result for m is I (2, m), the terminal measurement result for band m at wireless terminal 3 is I (3, m),..., the terminal measurement result for band m at wireless terminal n is I (n, m). Then, the addition average value A ₁ (m) of the terminal measurement results of the signal strength related to the band m of the wireless terminal existing in the service area of the own wireless base station 1 is
A ₁ (m) = {I (1, m) + I (2, m) + I (3, m) +... + I (n, m)}
/ N (5)
As given.

Here, if the measurement result transmitted from each wireless terminal existing in the service area of the wireless base station 1 is as shown in FIG. 15 described above, the addition average value A ₁ (m) (m = 1) of each band. To 10) are calculated as follows.

A ₁ (1) = {(− 84) + (− 115) + (− 103) + (− 122)
+ (− 98) + (− 102) + (− 84) + (− 93)} / 8
= -100.1 dBm
A ₁ (2) = -102.9 dBm
A ₁ (3) = − 114.4 dBm
A ₁ (4) = − 118.4 dBm
A ₁ (5) = − 124.4 dBm
A ₁ (6) = −134.8 dBm
A ₁ (7) = − 129.4 dBm
A ₁ (8) = − 123.4 dBm
A ₁ (9) = -125.0 dBm
A ₁ (10) = − 121.4 dBm
Then, in the comparator 10ED ₂ of communication frequency band determiner 10ED, average calculator 10ED average value of each band output from the _{1 A 1 (m) (m} = 1~10) and for the determination of free frequency Is compared with a predetermined threshold value, for example, -120 dBm, and a band lower than the threshold value is determined to be empty. Therefore, when the above-described addition average value A ₁ (m) is obtained based on the measurement result of FIG. 15, the six bands A ₁ (5) to A ₁ (10) have a threshold value of −120 dBm or less. The six bands are vacant frequency bands that are not used around the radio base station 1 and are output as frequency bands that do not cause interference with other radio communication systems.

Next, in the frequency determinator 10eD ₃ of the communication frequency band determinator 10eD, the value of the addition average value A ₁ (m) is the smallest among the six bands that are regarded as empty frequency bands in the comparator 10eD ₂ . The level band is determined to be the frequency band having the smallest amount of interference around the radio base station 1, and the band having the smallest value of the addition average value A ₁ (m) is determined as the frequency band used for communication.

That is, in the addition average value A ₁ (m) as described above based on the measurement result of FIG. 15, the center frequency of 2.455 GHz and the band of band number 6 indicating A ₁ (6) = − 134.8 dBm is the smallest value. The width of 10 MHz is determined to be used for communication with the wireless terminal as the frequency band with the least interference.

Further, as in the case of the second embodiment, other radio base stations located in the vicinity of the own radio base station 1 (in this embodiment, all the radio base stations 2, 3, 4, It is also possible to consider the addition average value A _j (m) transmitted from the four radio base stations (5).

In the second embodiment using the determination result L _j (m) in another radio base station, the radio base station (radio base station 2, In this embodiment using the addition average value A _j (m) of the terminal measurement results at other radio base stations, as described above, As a base station, a wider range of radio base stations may be targeted, for example, four radio base stations 2, 3, 4, and 5 existing in the vicinity of the radio base station 1 may be targeted. .

When the addition average value A (m) of the terminal measurement results of other nearby radio base stations is also used, the addition average value A ₁ (m) calculated by the equation (5) is transmitted to the other radio base stations. At the same time, the addition average value A _j (m) (j = 2, 3, 4, 5) transmitted from the other adjacent base station is used by using Formula (6) further incorporated in Formula (5). The determination of the free frequency band is performed.

That is, the addition average values A _j (m) transmitted from all the radio base stations 2, 3, 4 and 5 existing in the vicinity of the own radio base station 1 are respectively A ₂ (m) and A ₃ (m). , A ₄ (m), A ₅ (m), the addition average value A ₂ (m), A ₃ (m), A ₄ (m) is further added to the addition average value A ₁ (m) of Expression (5). , A ₅ (m) is added, and the total addition average value A ₁ ′ (m) is obtained by the following equation (6).

A ₁ ′ (m) = [{I (1, m) + I (2, m) + I (3, m) +
... + I (n, m)}
+ A ₂ (m) + A ₃ (m) + A ₄ (m) + A ₅ (m)] / (n + 4)
... (6)
In the case where the addition average value A _j (m) transmitted from all the radio base stations 2, 3, 4 and 5 existing in the vicinity is also used, in the comparator 10eD ₂ of the communication frequency band determiner 10eD, In place of the addition average value A ₁ (m) of the equation (5), the total frequency average value A ₁ ′ (m) of the equation (6) including the addition average value of other radio base stations is used, The free frequency band is extracted as compared with the threshold value for determination. Here, also in the calculation result of Expression (6) in which the addition average value A _j (m) of other radio base stations is taken into account, when the total addition average value A ₁ ′ (6) is the smallest value, It is determined that the center frequency of 2.455 GHz and the bandwidth of 10 MHz are used for communication with the wireless terminal.

The band m where the total addition average value A ₁ ′ (m) is a threshold value, for example, −120 dBm or less and the smallest value is not only the own radio base station 1 but also all other radios existing in the vicinity. Taking the base stations 2, 3, 4, and 5 into consideration, the result of the averaging of the addition average value A ₁ (m) of the terminal measurement results is a low level signal strength of a predetermined threshold value, for example, −120 dBm or less. This means that the signal strength is the smallest, and it is possible to more reliably determine that there are no radio waves of other wireless communication systems around the wireless base station 1.

In this embodiment, the third and fourth embodiments have been described in calculating the total addition average value A ₁ ′ (m) by applying the addition average value A _j (m) from other radio base stations. As described above, the weighted correction value corresponding to the distance from the wireless base station 1 is used to weight-correct the addition average value A _j (m) from other wireless base stations, and then applied to Equation (6). Also good.

Based on the calculation result of the addition average value A ₁ (m) or the total addition average value A ₁ ′ (m) as described above, in the frequency determiner 10eD ₃ of the communication frequency band determiner 10eD of the radio base station 1, the radio communication is performed. Determine the frequency and bandwidth used for. In the case of the above numerical example, it is considered that the band number 6 is an empty frequency band with the least interference. Therefore, the radio base station 10D radio base station frequency determiner 10ED ₃ of the communication frequency band determiner 10ED 1 having the structure of FIG. 26, the center frequency 2.455GHz band number 6, the bandwidth 10 MHz, the communication start It decides to use for communication with the wireless terminal 30D that has transmitted the request packet, and sets the frequency and bandwidth of the wireless signal processing unit 10h shown in FIG. Further, as shown in the flowchart of FIG. 10, at the same time, the frequency instruction packet storing the frequency / bandwidth information decided to be used for the communication of the radio terminal 30D via the base station-terminal interface unit 10f is stored. The communication start request packet is transmitted to the wireless terminal 30D that is the transmission source (step S14). The wireless terminal 30D receives this frequency instruction packet (step S15), sets the frequency / bandwidth of the wireless signal processing unit 30b shown in FIG. 25, and starts communication.

As described above, the communication frequency band determiner 10eD is transmitted from the terminal measurement result of the signal strength of the wireless terminal existing in the service area of the own wireless base station 1 and the other wireless communication station devices 2, 3, 4, and 5. and the terminal measurement results of the signal strength of the wireless terminals present in each service area, for all the frequency bands of the utilization object, for each frequency band, a mean calculator 10ED ₁ average calculation means for calculating a result of the averaging, comparing the result of the addition average by the mean calculator 10ED _1, compared with a predetermined threshold value for the available frequency determination, and outputs the determination result of the signal strength indicating whether vacant frequency in vicinity of the own wireless communication station a vessel 10ED _2, by providing at least the terminal measurement results of the signal strength of the neighboring radio terminals existing in the service area of its own, other radio base stations Averaging results make it possible to determine the smallest value to become equal to or smaller than the threshold band, with, it is possible to obtain a determination result of the accurate free frequencies than at near the radio communication station.

More specifically, the radio base station 1 is located not only in the addition average value of the terminal measurement results of the signal strength of the radio terminal in the radio base station 1 but also in the vicinity as the frequency band of the radio signal used for the current communication. Using the total addition average value A ₁ ′ (m) including the terminal measurement results of the signal strengths of the radio terminals in all other radio base stations 2, 3, 4, and 5 A band for which the average of the terminal measurement results of the signal strength of wireless terminals existing in the area is equal to or less than a predetermined threshold for determining a free frequency and has the smallest signal strength is the frequency for this communication. Since the system decides to use it as a band, even if the radio waves from other wireless communication systems are temporarily weakened by obstruction, fading, etc. Or Ttei also radio wave detector 30e bandpass filter 30e ₃ of, even errors in some cases you are or generated in the detection precision of an instrument of some wireless terminals for detecting a free frequency, radio The probability of causing erroneous detection of empty frequencies around the base station 1 can be reduced, and the detection accuracy of empty frequencies can be further increased.

  In the above-described embodiment, the terminal measurement result of the signal strength of the wireless terminal in the own wireless communication station device and the terminal measurement result of the signal strength of the wireless terminal in the other wireless communication station device transmitted from the other wireless communication station device. As an example of calculating the frequency band in which the signal intensity of the smallest value below the threshold is calculated as a result of averaging the above, the present invention is not limited to such a case. For example, as described above in the third and fourth embodiments, after performing weight correction on the terminal measurement result of the signal strength of another radio base station, 1 to 1 existing in the service area of the own radio base station You may make it average addition with the terminal measurement result of the signal strength of the said several radio | wireless terminal.

(Sixth embodiment)
Next, a sixth embodiment relating to a wireless communication system, a wireless communication station apparatus (wireless base station), a wireless terminal apparatus (wireless terminal), and a wireless communication method according to the present invention will be described. In the present embodiment, unlike each of the embodiments described above, not only the frequency band used for communication is determined on the radio base station side, but also the case where the communication method and transmission power used for communication are also determined. .

  In this embodiment, the system configuration of the wireless communication system and the distance between the wireless base stations are the same as those in FIGS. 1 and 2, respectively. FIG. 29 shows the configuration of the wireless terminal in this embodiment. FIG. 29 is a block configuration diagram showing an example of a block configuration of a wireless terminal in the sixth embodiment of the present invention. In this embodiment, information on the communication method and / or transmission power amount is exchanged with the wireless base station. 3 shows an example having a configuration substantially similar to that of the wireless terminal 30 shown in FIG. 3 as the first embodiment except that transmission / reception is further possible.

  In the wireless terminal 30E of FIG. 29, the switch 30c is connected to the A side during the communication start process, the wireless signal processing unit 30bE is connected to the base station-terminal interface unit 30dE, and the base station-terminal interface unit 30dE At the same time as the instruction regarding the frequency band to be used for communication in the future, an instruction regarding the communication method and / or transmission power used for the communication is transmitted to the radio signal processing unit 30bE. On the other hand, the switch 30c is connected to the B side during normal communication, and the radio signal processing unit 30bE is connected to an upper layer processing unit (not shown).

  That is, the wireless terminal 30E receives the frequency / communication method instruction packet from the wireless base station at the base station-terminal interface unit 30dE during the communication start process, and the frequency and communication method indicated in the frequency / communication method instruction packet. In addition, the transmission power amount is transmitted to the radio signal processing unit 30bE via the switch 30c.

  Next, the configuration of the radio base station in the present embodiment is shown in FIG. FIG. 30 is a block configuration diagram illustrating an example of a block configuration of a radio base station according to the sixth embodiment of the present invention. Each of the radio base stations 1, 2, 3, 4 and 5 in FIG. 1 has the same configuration as that in FIG. The radio base station 10E shown in FIG. 30 is, for example, the radio shown in FIG. 18 in the third embodiment except that it is possible to handle information related to the communication method and / or transmission power in addition to the frequency band used for communication. This is the same as in the case of the base station 10B. That is, as described above, the radio base station 10E in FIG. 30 uses the communication frequency band, the communication method, and / or the transmission instead of the communication frequency band determiner 10eB installed in the radio base station 10B shown in FIG. A communication frequency band / communication method determiner 10eE that determines both the amount of power and a radio signal processing unit 10h and a base station-terminal interface unit 10f installed in the radio base station 10B shown in FIG. 18 are used. In addition, a configuration example including a radio signal processing unit 10hE that handles both information of a communication frequency band and a communication method and a base station-terminal interface unit 10fE is shown.

FIG. 31 shows an example of the configuration of the communication frequency band / communication method determiner 10eE installed in the radio base station 10E of FIG. FIG. 31 is a block configuration diagram showing an example of the configuration of the communication frequency band / communication method determiner 10eE of the radio base station 10E shown in FIG. As shown in FIG. 31, the frequency band and communication scheme determining apparatus 10eE communication, instead of the frequency determiner 10eB ₄ of the communication frequency band determiner 10eB of Figure 19 in the third embodiment, the frequency and communication scheme determining except that has a vessel 10EE ₄ has the same configuration as the communication frequency band determiner 10eB in Figure 19. In addition, although the case where the same structure as the communication frequency band determinator 10eB of FIG. 19 of the third embodiment is used will be described here, the present invention is not limited to this case. The present invention may be applied to communication frequency band determiners 10e, 10eA, 10eC, and 10eD in other embodiments. That is, for example, in the same structure as the communication frequency band determiner 10e of Figure 6 in the first embodiment, instead of the frequency determiner 10e ₃ of the communication frequency band determiner 10e, frequency and communication scheme determining apparatus 10eE ₄ may be provided.

  The radio base station 10E determines a communication frequency band, a communication method, and / or a transmission power amount used for communication with the wireless terminal 30E in the communication frequency band / communication method determiner 10eE. The determined frequency band, communication method, and transmission power amount are transmitted to the base station-terminal interface unit 10fE and the radio signal processing unit 10hE. The base station-terminal interface unit 10fE receives the communication start request packet from the wireless terminal 30E, and creates a frequency / communication mode instruction packet for instructing the frequency / bandwidth / communication method / transmission power used for communication. The communication start request packet is transmitted to the wireless terminal 30E that is the transmission source. The radio signal processing unit 10hE sets the frequency, bandwidth, communication method, and transmission power amount used for communication with the wireless terminal 30E according to an instruction from the communication frequency band / communication method determiner 10eE.

  Hereinafter, with respect to the present embodiment using the radio terminal 30E and the radio base station 10E configured as shown in FIG. 29 and FIG. 30, the frequency and bandwidth of the radio signal used for communication in the radio base station 1 shown in FIG. Processing will be described with reference to the flowcharts of FIGS. 7 and 32 showing an example of the wireless communication method of the present invention. As described above, the configuration of the radio terminal includes the configuration of the radio terminal 30E as illustrated in FIG. 29. As described above, the configuration of the radio base station 1 includes the radio base station 10E as illustrated in FIG. It shall consist of the following.

  In this embodiment, in the radio base station 1 of FIG. 1 having the configuration of the radio base station 10E, the signal strength of the radio signal is measured in order to detect the free frequency of the radio signal, as in the first embodiment. Two processes, a radio wave detection process to be performed and a communication start process to perform a series of processes from determination of a frequency band used for communication to the start of communication, are performed. The radio wave detection process is periodically executed at a predetermined cycle, and the communication start process is executed with a communication start request from a communication start request packet from a wireless terminal as a trigger.

  First, an example of radio wave detection processing in the present embodiment of the radio base station 1 having the configuration of the radio base station 10E of FIG. 30 will be described with reference to FIG. The radio wave detection process in the present embodiment of the radio base station 1 for detecting the free frequency of the radio signal is substantially the same as the flowchart of FIG. 7 in the first embodiment.

  In FIG. 7, first, a timer synchronized between all the radio base stations is set to time until a predetermined time period (step S1), and the timer reaches a predetermined time period (no in step S3). Then, the reduction process is performed (step S2), and when the timer expires (yes in step S3), the radio wave detection process is started.

When radio wave detection processing is started in the radio wave detector 10c shown in FIG. 5 provided in the radio base station 10E of FIG. 30, the radio wave detector 10c sets the frequency band 2.4 GHz-2.5 GHz of the candidate for use to 10 MHz. Separate the plurality of bands having a width of (10 bands in the present embodiment), the center frequency of the bandpass filter 10c ₃ is, between the 2.405GHz the center frequency of each band up to 2.495GHz, i.e. Until the measurement of the signal intensity in all frequency bands is completed (no in step S5), the center frequency is sequentially changed by 10 MHz (step S6), and each band of the radio signal received by the radio wave detection antenna 10b is measured. Is measured by the power measuring device 10c ₄ as the signal strength (step S4).

  When the measurement of the signal strength in all frequency bands is completed (yes in step S5), the signal strength measurement result is then transmitted to other radio base stations via the signal lines 21,..., 27 shown in FIG. Are exchanged (step S7). Here, in the present embodiment, the radio base station exchanging the signal strength measurement results is the same as the third embodiment in that the radio base station exists within a circle with a radius of 5 km centered on the own radio base station. The information to be exchanged with other radio base stations is not limited to all radio base stations (radio base stations 1, 2, 3, 4, 5 in this embodiment) existing in the vicinity. As in the case of the third embodiment, the measurement result is limited to only the signal strength measurement result, and the determination result obtained by comparing the measurement result with a threshold value, for example, −120 dBm, is not exchanged.

  Here, in the radio base station 1, the measurement result of the signal strength of the radio base station 1 itself and the signal strength transmitted from each of the radio base stations 2, 3, 4 and 5 existing in the vicinity of the radio base station 1 As for the measurement results, it is assumed that the results shown in FIG. 20 described above in the third embodiment are obtained.

  The measurement result of the signal strength as shown in FIG. 20 is input to the communication frequency band / communication method determiner 10eE. In the communication frequency band / communication system determiner 10eE, based on the signal strength measurement results in the plurality of radio base stations of the own radio base station 1 and the other radio base stations 2, 3, 4 and 5, the radio base station In addition to extracting a free frequency band that is not currently used in the vicinity of 1, the wireless terminal that is the transmission source of the communication start request packet determines a free frequency band, a communication method, and / or a transmission power amount used for the current communication. .

  Next, in the present embodiment of the radio base station 1 having the configuration of the radio base station 10E of FIG. 30, an example of an operation for performing communication start processing of the radio terminal will be described with reference to FIG. FIG. 32 is a flowchart illustrating an example of an operation for performing communication start processing of a wireless terminal in the wireless base station 1 according to the sixth embodiment of the present invention. A square box indicates processing on the wireless base station 1 side. A box with rounded corners indicates processing on the wireless terminal 30E side.

  Prior to starting communication by connecting to the network, the wireless terminal 30E sends a communication start request packet and a frequency / communication method instruction packet to and from the wireless base station 1 in the service area in which the wireless terminal 30E exists. Send and receive.

  In the flowchart of FIG. 32, first, the wireless terminal that has the configuration of the wireless terminal 30E of FIG. 29 and requests the start of communication transmits a communication start request packet via the base station-terminal interface unit 30dE of FIG. It transmits with respect to the wireless base station 1 which consists of a structure of the wireless base station 10E of FIG. 30 (step S41). When the wireless base station 1 receives the communication start request packet from the wireless terminal 30E via the wireless base station-terminal interface unit 10fE in FIG. 30 (step S42), the wireless base station 1 in the communication frequency band / communication method determiner 10eE Then, the determination process of the frequency band, communication method, and / or transmission power amount used by the wireless terminal 30 for the current communication is performed according to the following procedure (step S43).

In the communication frequency band / communication method determiner 10eE of the radio base station 1 having the configuration of the radio base station 10E of FIG. 30, first, the weight corrector 10eB ₁ shown in FIG. The signal strength measurement result is multiplied by weighting factors w ₁ , w ₂ , and w ₃ as weight correction values using the method shown in the third embodiment.

Thereafter, in the adder 10eB ₂ of communication frequency bands and communication scheme determination unit 10EE, for each band m, the weight coefficient _{w 1,} w 2, _{w 3} signals of each radio base station which is corrected by weighting with The intensity measurement results are added, and the combined corrected signal intensity SP ₁ (m) in the band m of the radio base station 1 is calculated by the equation (4) described in the third embodiment.

Assuming that the signal strength measurement results at each of the radio base stations 1, 2, 3, 4 and 5 are as shown in FIG. 20, using the equation (4), for each band m in the radio base station 1 shown in FIG. The calculation result obtained by calculating the correction signal intensity SP ₁ (m) is given as shown in FIG. 33 as described above in the third embodiment. That is, FIG. 33, in this embodiment, a table showing a specific example of the correction measurement That correction signal strength SP 1 _(m) obtained by correcting the results of measuring the power of each band number in the radio base station 1 shown in FIG. 1 is there.

Next, in the comparator 10eB ₃ of the communication frequency band / communication method determiner 10eE, the signal strength after the weight correction of the radio signal output from the adder 10eB _2, that is, the corrected signal strength SP ₁ (m) is determined as the free frequency. Compared with a predetermined threshold for determination, for example, −120 dBm, a band lower than the threshold is determined to be empty. Therefore, when the correction signal intensity SP ₁ (m) of each band as shown in FIG. 33 is obtained, the frequency / communication method determiner 10eE ₄ compares the comparison result from the comparator 10eB ₃ (whether it is an empty frequency or not). The band determined to be a vacant frequency band from the determination results indicating band numbers 4, 5, and 6 corresponding to the correction signal intensities SP ₁ (4), SP ₁ (5), and SP ₁ (6) It can be considered that the numbers 4, 5, and 6 are vacant frequency bands.

Further, among these three bands, the band with the lowest correction signal intensity SP ₁ (m) (that is, the band number 5 in the above case) is determined to be the band with the least amount of interference, and the band is Decide to use for communication.

Further, in the frequency / communication system determiner 10eE ₄ of the communication frequency band / communication system determiner 10eE, unlike the third embodiment, no radio signal exists in the vicinity of the own radio base station 1. When determining whether or not the frequency is a free frequency and determining the frequency band of the radio signal used for communication with the radio terminal, it is determined including the communication method and / or the transmission power amount, and the corrected signal strength Depending on the value of SP ₁ (m), a communication method and / or transmission power amount used for communication is also selected.

In general, the lower the value of the correction signal strength SP ₁ (m) related to the radio signal calculated in the radio base station 1, the smaller the amount of interference with another radio communication system, so the communication antenna 10a. It is possible to increase the transmission power amount of the radio signal transmitted from. Moreover, the higher the transmission power amount, the faster the transmission rate can be used.

FIG. 34 shows an example of a communication method and transmission power corresponding to the value of the correction signal strength SP ₁ (m) in the present embodiment. As a communication method shown in FIG. 34, OFDM (Orthogonal Frequency Division Multiplexing) and SS (Spread Spectrum) are used, and 64QAM (Quadrature Amplitude Modulation) and 16QAM are used as modulation methods. , QPSK (Quadrature
In this example, phase shift keying (four phase shift keying) and BPSK (binary phase shift keying) are assumed.

In FIG. 34, SF indicates a spreading factor in SS (spread spectrum). When determining the communication method according to FIG. 34, for the band number 5 determined for communication based on the result of the correction signal strength SP ₁ (m) shown in FIG. 33, the correction signal strength SP ₁ (m) = −. Since it is 131.5 dBm, according to the communication method and transmission power amount of FIG. 34, SS (SF = 2) · BPSK is extracted as the communication method, and 2 mW is extracted as the transmission power amount. It is determined as the communication method to be used and the transmission power amount.

From the calculation results described above, in the communication frequency band and communication scheme determining unit frequency-communication mode determination unit 10EE ₄ of 10EE radio base station 1, together considered as optimal vacant frequency bands using a band number 5 in the communication The communication method can be determined as SS (SF = 2) · BPSK, and the transmission power amount can be determined as 2 mW. Therefore, the frequency / communication method determiner 10eE ₄ of the communication frequency band / communication method determiner 10eE of the wireless base station 1 having the configuration of the wireless base station 10E of FIG. 30 has a center frequency of 2.445 GHz and a band of band number 5. The width 10 MHz is determined to be used for communication with the wireless terminal 30 that has transmitted the communication start request packet, the communication method is determined to be SS (SF = 2) · BPSK, and the transmission power amount is determined to be 2 mW, The frequency, bandwidth, communication method, and transmission power amount of the radio signal processing unit 10hE shown in FIG. 30 are set (step S44). Furthermore, as shown in the flowchart of FIG. 32, the frequency / bandwidth information and the communication method / transmission power determined to be used for communication of the radio terminal 30E via the base station-terminal interface unit 10fE at the same time. Is transmitted to the wireless terminal 30E which is the transmission source of the communication start request packet (step S45). The wireless terminal 30E receives the frequency / communication method instruction packet (step S46), sets the frequency / bandwidth / communication method / transmission power amount of the wireless signal processing unit 30b shown in FIG. 3, and starts communication. .

As described above, as the frequency band of the radio signal used for the current communication, not only the measurement result of the signal strength of the radio terminal in the radio base station 1, but also all other radio base stations 2, 3, Using the measurement results of the signal strengths at 4 and 5, the correction signal strength weight-corrected by the weight correction values of all of its own and other radio base stations is less than or equal to a predetermined threshold for vacant frequency determination and is the smallest The band with the signal strength of the value is decided to be used as the frequency band for the current communication, and the most suitable communication method and / or transmission power amount is also combined with the corrected signal strength subjected to the weight correction. Therefore, even if radio waves from other wireless communication systems are temporarily received due to obstructions or fading by obstacles, etc. Or are weakened, also radio wave detector 10c bandpass filter 10c ₃ of, even errors in some cases you are or generated in the detection precision of an instrument portion of the radio base station for detecting a free frequency The probability of causing false detection of empty frequencies around the radio base station 1 can be reduced, the detection accuracy of empty frequencies can be further increased, and the optimum transmission rate can be reduced while minimizing the possibility of interference. Wireless communication can be performed.

  In the above description of the present embodiment, as in the third embodiment, the frequency, bandwidth, communication method, and transmission power used for communication are determined based on the corrected signal intensity that is weight-corrected using the weighting coefficient corresponding to the distance. The case of determining the amount has been described. However, as described above, the present invention is not limited to such a case. As in the fourth embodiment, correction using the propagation loss amount as a weight correction value according to the distance is performed. The signal strength may be used, the measurement result or determination result itself of the own or other radio base station may be used, or the terminal measurement result or terminal of the signal strength of the radio terminal in the own or other radio base station The determination result itself may be used, or a result obtained by averaging the terminal measurement results of the signal strength of the wireless terminal in the own / other wireless base stations may be used.

  In this embodiment, the frequency band used for communication is determined, and at the same time, the communication method and / or transmission power amount used for communication is determined. Both the communication method and the transmission power amount may be determined. In some cases, however, only the communication method or only the transmission power amount may be determined.

(Seventh embodiment)
Next, a seventh embodiment relating to a wireless communication system, a wireless communication station device (wireless base station), a wireless terminal device (wireless terminal), and a wireless communication method according to the present invention will be described. In this embodiment, the system configuration of the wireless communication system and the distance between the wireless base stations are the same as those in FIGS. 1 and 2, respectively. In addition, the configuration of the wireless terminal in this embodiment is the same as that of the first embodiment shown in FIG.

The configuration of the radio base station is the same as the radio base station 10B of FIG. 18 equipped with the communication frequency band determiner 10eB of FIG. 19 of the third embodiment or the communication frequency of FIG. 22 of the fourth embodiment. The configuration is almost the same as that of the radio base station 10C of FIG. 21 equipped with the band determiner 10eC. However, in this embodiment, the third embodiment or the fourth embodiment in shown, the weight corrector 10eC weight corrector 10eB ₁ or communication frequency band determiner 10eC of communication frequency band determiner 10eB ₁ , when weighting and correcting the measurement result of the radio base station by multiplying the weighting factor or adding the propagation loss amount as the weight correction value, if the communication environment is only the distance between the radio base stations, First, an example in which the weighting factor or the weight correction value of the propagation loss amount can be appropriately changed and set according to the communication time zone and the installation location of the radio base station is shown.

  For example, as a communication environment in which each wireless base station is installed, the weight correction value for weighting the measurement result of the signal strength is changed and set in consideration of geographical factors such as mountains and buildings. Anyway. Also, when there is a correlation between the change in the number of interference signals or the change in the signal strength of the interference signal and the time zone, the weight correction value for weighting the signal strength measurement results is changed based on the time zone. You may make it set.

  In addition, by using Bayesian estimation, which is a statistical prediction method, weight correction that predicts the occurrence of interference signals and the signal strength of interference signals and weights the measurement results of signal strength based on the prediction results The value may be changed and set. Alternatively, based on the past interference signal generation time and the signal strength of the interference signal (that is, interference occurrence history information in the past communication), the generation time of the interference signal that may occur in the future and the signal strength of the interference signal are predicted. The weight correction value for weighting the signal intensity measurement result may be changed and set.

  Furthermore, it is also possible to determine an optimum weighting method for the weight correction value for weighting the measurement result of the signal strength by repeating an iterative calculation using an adaptive algorithm. For example, by using a LMS (Least Mean Square) algorithm, which is one of adaptive algorithms, by transmitting a reference signal from each radio base station or radio terminal to each radio base station at a predetermined time interval, Each radio base station may change and set a weight correction value for weighting the measurement result of the signal strength based on the received reference signal from each radio base station or radio terminal.

  In addition, using a neural network, it is possible to predict the generation of interference signals based on past interference signal generation results and change and set the weight correction value for weighting the signal intensity measurement results. .

(Eighth embodiment)
Next, an eighth embodiment relating to a wireless communication system, a wireless communication station apparatus (wireless base station), a wireless terminal apparatus (wireless terminal), and a wireless communication method according to the present invention will be described. In the present embodiment, when weighting correction is performed on the signal strength measurement result of each radio base station in the process of determining the communication frequency and communication method on the radio base station side, the third embodiment and the fourth embodiment described above are used. Unlike the case of the embodiment, when performing weight correction in consideration of a shadowing environment in which there is a correlation with the received power measurement value of each radio base station existing in the vicinity, One example will be described.

  That is, in the present embodiment, the communication frequency and communication method are determined for the wireless base station that exists within the predetermined distance threshold Dth from the wireless base station that determines the communication frequency and communication method. Assuming that the received power measurement value is correlated with the radio base station due to shadowing, the weighting coefficient is set to “0” according to the degree of correlation with the received power measurement value, and the distance threshold value Dth This shows a case where the measurement result of the signal strength of the wireless base station existing within the range is not reflected in the determination process of the communication frequency and communication method.

  Here, the shadowing in which correlation occurs is a measured value of received power (that is, a measured value of signal strength) measured at each of a plurality of radio stations (that is, a radio base station and a radio terminal) existing in close proximity to each other. ) Means that there is a correlation with each other.

  For example, in a shadowing environment having a correlation, as described in the IEEE standard (IEEE C802.16j-06 / 045r1), when the distance between wireless stations is Δx [m], the received power measurement value Can be expressed as the following equation (7).

ここで、ｄ_ｃｏｒは、シャドウイングの影響度の目安を示す距離定数であり、屋外においては、一般に、２０［ｍ］とされている。

Here, d _cor is a distance constant indicating a measure of the influence of shadowing, and is generally set to 20 [m] outdoors.

  FIG. 35 shows how the correlation coefficient ρ changes with respect to the distance Δx [m] between wireless stations shown in Expression (7). FIG. 35 is a correlation diagram showing how the correlation coefficient ρ of the received power measurement value at each wireless station changes with respect to the distance Δx [m] between the wireless stations (wireless base station, wireless terminal). As shown in Expression (7) and FIG. 35, the closer the distance Δx [m] between the radio stations is, the closer the correlation coefficient ρ of the received power measurement value is to “1”. When the correlation coefficient ρ approaches “1”, it means that the received power measurement values at both radio stations approach the same value. That is, the difference in the received power measurement values at the radio stations having a short distance between the radio stations becomes small.

  For example, in the case where the weighting factor correction method in the third and fourth embodiments is applied, in a shadowing environment with correlation, interference with frequencies used in other wireless communication systems is avoided. There is a risk of reducing the effect. That is, in the third and fourth embodiments, even if the received power measurement value at the own radio base station is temporarily low due to the influence of an obstacle (such as a building or a tree), The received power measurement value at the other radio base station is weighted and corrected to be used for vacant frequency determination. In either of the third and fourth embodiments, the closer the distance from the own radio base station is, The weighting is performed so as to increase the weight for the received power measurement value of the other radio base station.

  However, in a shadowing environment where the received power measurement value is correlated, as described above, the received power measurement value at other radio base stations around the own radio base station is close to the own radio base station. The closer to the received power measurement value at the own radio base station, the closer the position of the other radio base station around the own radio base station is to the own radio base in the third and fourth embodiments. Since the weight for the received power measurement value of the other radio base station is set to be greater as the position is closer to the base station position, the received power measurement value of the other radio base station is closer to the position of the own radio base station. Even if an attempt is made to use the received power measurement values at other radio base stations in the vicinity, the interference avoidance effect in determining the free frequency may be reduced.

  In the present embodiment, such a situation is taken into consideration, and in the communication frequency determination process on the radio base station side, each radio base station is used by using a weight correction value according to the distance between each radio base station. Unlike the third and fourth embodiments, when performing the weighting correction on the signal strength measurement results, the radio base station that determines the communication frequency and communication method is within a predetermined distance threshold Dth. For existing radio base stations, the weight correction value is assumed to be affected by shadowing that correlates the received power measurement value with the radio base station that determines the communication frequency and communication method. The case where the weighting factor is set to “0” and the measurement result of the signal strength of the radio base station existing within the range of the distance threshold value Dth is not reflected in the determination process of the communication frequency and communication method is shown. .

Further description is as follows. In the third and fourth embodiments, in the process of detecting the vacant frequency, for example, as shown in the calculation formula of the correction signal strength SP ₁ (m) shown in the formula (4), it corresponds to the distance between the radio base stations. That is, as shown in FIG. 36, the value of the weight coefficient for correcting the signal strength is determined in inverse proportion to the distance between the own radio base station and the other radio base station. FIG. 36 is a schematic diagram illustrating an example of a determination method for determining the value of the weighting coefficient according to the distance between the radio base stations, and illustrates the case of application in the third embodiment.

  As shown in FIG. 36, in the third embodiment, the received power measurement value (signal strength measurement value) is closer to another radio base station that is closer to the own radio base station that determines the communication frequency band and communication method. Is set to a large value, and the influence of the received power measurement value of another radio base station close to the position of the own radio base station is increased. As a result, even if the received power measurement value at another radio base station is used, it is affected by shadowing that causes a correlation with respect to the received power measurement value, which may reduce the interference avoidance effect in determining the free frequency. Occurs.

On the other hand, in this embodiment, in the calculation formula of the correction signal strength SP ₁ (m) used when performing the process of detecting the vacant frequency, as shown in FIG. ) And the distance between the radio base stations, the value of the weighting factor for correcting the signal strength measurement value is determined. FIG. 37 is a schematic diagram showing an example of a determination method for determining the value of the weighting factor in accordance with the communication environment and the distance between the radio base stations, and other radio base stations and shadows existing in a shadowing environment like this. An example is shown in which a weighting factor for weight correction of a received power measurement value is determined by a different method with another radio base station existing outside the inning environment.

  That is, as shown in FIG. 37, the weighting factor for other radio base stations existing within a predetermined distance threshold Dth as being within a shadowing environment is “0”, and the distance from the own radio base station is close. The received power measurement values of other radio base stations in the shadowing environment should not be reflected in the determination process of the communication frequency and communication method, while existing in the range exceeding the distance threshold Dth and outside the shadowing environment For a certain other radio base station, as in the case of the third embodiment shown in FIG. 36, the value of the weight coefficient for correcting the signal strength in inverse proportion to the distance between the own radio base station and the other radio base station. To be determined.

  The system configuration of the wireless communication system in the present embodiment is the same as that of the first embodiment shown in FIG. Further, the configuration of the wireless terminal in this embodiment is the same as that of FIG. 3 of the first embodiment, and the configuration of the wireless base station is the case of FIG. 18 or FIG. 21 of the third or fourth embodiment. It is the same. That is, each of the wireless terminals 31, 32, 33,... Shown in FIG. 1 has the configuration of the wireless terminal 30 shown in FIG. 3, and each of the wireless base stations 1, 2, 3, 4, 5 is for communication in FIG. The radio base station 10B of FIG. 18 provided with the frequency band determiner 10eB or the radio base station 10C of FIG. 21 provided with the communication frequency band determiner 10eC of FIG.

  However, the distance between the radio base stations is as shown in FIG. 38, unlike the case of FIG. 2 of the first embodiment. FIG. 38 is a diagram showing another example of the distance between a certain radio base station shown in FIG. 1, for example, the radio base station 1, and other neighboring radio base stations 2, 3, 4, and 5 different from FIG. FIG.

  As shown in FIG. 38, the distance from the radio base station 1 to the other radio base stations 2, 3, 4 and 5 is closer to the radio base station 1 than in the case of FIG. , 40 m, 20 m, and 60 m. As shown in FIG. 38, since the distance between the radio base stations is on the order of several tens of meters to several hundreds of meters, the received power measurement value, that is, the signal strength measurement value is a shadow that has a correlation between the radio base stations. Will be affected by Ying. Here, when the distance between radio base stations is set to, for example, 30 m as the distance threshold value Dth at which the correlation of the received power measurement value under the shadowing environment will occur, when determining the communication frequency and communication method The received power measurement values of the radio base stations 2 and 4 existing within the distance threshold Dth, for example, 30 m from the radio base station 1 are assumed to be in a shadowing environment, and the weight coefficient is set to “0”. The reception power measurement values of the radio base stations 2 and 4 are set not to be used.

  That is, as shown in the third embodiment, when the received power measurement value (signal strength) is multiplied as a weight correction value, the weights of the radio base stations 2 and 4 in the shadowing environment are When the coefficient is set to “0” and the propagation loss amount is added as a weight correction value to the received power measurement value (signal strength), the radio base stations 1 and 2 in the shadowing environment And a predetermined value, for example, “0” dBm.

  In the following, with respect to the present embodiment using the radio terminal 30 and the radio base station 10B configured as shown in FIGS. 3 and 18, determination of the frequency and bandwidth of the radio signal used for communication in the radio base station 1 shown in FIG. Processing will be described with reference to the flowcharts of FIGS. 7 and 10 showing an example of the wireless communication method of the present invention. The case where the radio base station has the configuration of the radio base station 10B of FIG. 18 will be described below, but the case where the radio base station has the configuration of the radio base station 10C of FIG. Yes, except that when the received power measurement value (signal strength measurement value) of each radio base station is weight-corrected, instead of multiplying by a weighting factor, a process of adding a propagation loss amount as a weight correction value is performed. This is exactly the same as the following description.

  In the present embodiment, in the radio base station 1 of FIG. 1 having the configuration of the radio base station 10B of FIG. 18, as in the first embodiment, the signal of the radio signal is detected in order to detect the free frequency of the radio signal. Two processes are performed: a radio wave detection process for measuring the intensity and a communication start process for performing a series of processes from the determination of the frequency band used for communication to the start of communication. The radio wave detection process is periodically executed at a predetermined cycle, and the communication start process is executed with a communication start request from a communication start request packet from a wireless terminal as a trigger.

  First, an example of radio wave detection processing in the present embodiment of the radio base station 1 having the configuration of the radio base station 10B in FIG. 18 will be described with reference to FIG. The radio wave detection process in the present embodiment of the radio base station 1 for detecting the free frequency of the radio signal is substantially the same as the flowchart of FIG. 7 in the first embodiment.

  In FIG. 7, first, a timer synchronized between all the radio base stations is set to time until a predetermined time period (step S1), and the timer reaches a predetermined time period (no in step S3). Then, the reduction process is performed (step S2), and when the timer expires (yes in step S3), the radio wave detection process is started.

When the radio wave detection process is started in the radio wave detector 10c shown in FIG. 5 provided in the radio base station 10B of FIG. 18, the radio wave detector 10c sets the frequency band 2.4 GHz-2.5 GHz of the candidate for use to 10 MHz. Separate the plurality of bands having a width of (10 bands in the present embodiment), the center frequency of the bandpass filter 10c ₃ is, between the 2.405GHz the center frequency of each band up to 2.495GHz, i.e. Until the measurement of the signal intensity in all frequency bands is completed (no in step S5), the center frequency is sequentially changed by 10 MHz (step S6), and each band of the radio signal received by the radio wave detection antenna 10b is measured. Is measured by the power measuring device 10c ₄ as the signal strength (step S4).

  When the measurement of the signal strength in all frequency bands is completed (yes in step S5), the signal strength measurement result is then transmitted to other radio base stations via the signal lines 21,..., 27 shown in FIG. Are exchanged (step S7). In this embodiment in which the signal strength measurement result is weight-corrected according to the distance between the radio base stations, the radio base station exchanging the signal strength measurement result is the same as the third embodiment. Not only radio base stations existing within a circle with a radius of 5 km centered on the station, but also all radio base stations existing in the vicinity (radio base stations 1, 2, 3, 4, 5 in this embodiment) Further, the information exchanged with other radio base stations is limited to the signal strength measurement result as in the case of the third embodiment, and the determination result comparing the measurement result with a threshold value, for example, -120 dBm. No action to replace.

  Here, in the radio base station 1, the measurement result of the signal strength of the radio base station 1 itself and the signal strength transmitted from each of the radio base stations 2, 3, 4 and 5 existing in the vicinity of the radio base station 1 The measurement results are as shown in FIG. FIG. 39 shows the measurement result of the power, that is, the signal strength for each band number in each radio base station shown in FIG. 1 (radio base stations 1, 2, 3, 4, and 5 in this embodiment) in this embodiment. It is a table to show.

  The measurement result of the signal strength as shown in FIG. 39 is input to the communication frequency band determiner 10eB in FIG. In the communication frequency band determiner 10eB, based on the signal strength measurement results in the plurality of radio base stations of the own radio base station 1 and the other radio base stations 2, 3, 4 and 5, the surroundings of the radio base station 1 In this step, a free frequency band that is not currently used is extracted, and a free frequency band that is used for the current communication by the wireless terminal that is the transmission start request packet is determined.

  Next, in the present embodiment of the radio base station 1 having the configuration of the radio base station 10B of FIG. In this embodiment, the flowchart of the radio base station 1 that performs the communication start process of the radio terminal 30 is almost the same as that in FIG.

  First, the wireless terminal having the configuration of the wireless terminal 30 of FIG. 3 and requesting the start of communication sends a communication start request packet to the wireless base station of FIG. 18 via the base station-terminal interface unit 30d of FIG. It transmits with respect to the wireless base station 1 which consists of a structure of 10B (step S11). When the radio base station 1 receives the communication start request packet from the radio terminal 30 via the radio base station-terminal interface unit 10f in FIG. 18 (step S12), the radio frequency base station 10eB performs the radio communication. The determination process of the frequency band used by the terminal 30 for the current communication is performed according to the following procedure (step S13).

In the communication frequency band determiner 10eB of the radio base station 1 having the configuration of the radio base station 10B of FIG. 18, first, in the weight corrector 10eB ₁ shown in FIG. 19, the signal strength of each radio base station shown in FIG. The measurement result is multiplied by a weight coefficient as a weight correction value. Here, the weighting coefficient to be multiplied as the weight correction value is determined between the communication environment (for example, an environmental condition indicating whether or not a shadowing environment in which a correlation is generated in the received power measurement value of the wireless base station) and between the wireless base stations. It is determined according to the distance.

For example, among the other radio base stations that have transmitted the measurement result weight w _o and the signal strength measurement result of the own radio base station, the distance determined in advance is assumed that the distance from the own radio base station is in a shadowing environment. The threshold value Dth, for example, the total number x of other radio base stations within 30 m, the weight w _x of each measurement result of the other radio base station, and the second distance that the distance from the own radio base station exceeds the distance threshold Dth, eg, 30 m The total number y of other radio base stations within the distance threshold of 50 m and the weight w _y of each measurement result of the other radio base station, the total number z of other radio base stations exceeding 50 m, and the weight w of each measurement result of the other radio base station _{When z} is set, it is determined according to the distance between the radio base stations as follows.

That is, the weighting factor w ₁ of the measurement result of the own radio base station is
w ₁ = w _o / s
Given in.

In addition, the weight coefficient w ₂ of the measurement result of each of the other radio base stations within a circle with a radius of 30 m centered on the own radio base station is
w ₂ = w _x / s
Given the weighting factor w ₃ of each of the other radio base station of the measurement results of the circle of radius 50m beyond the radius 30m around the radio base station is,
w ₃ = w _y / s
The weight coefficient w ₄ of the measurement result of each of the other radio base stations outside the circle with a radius of 50 m centered on the own radio base station is
w ₄ = w _z / s
Given in.

Here, the variable s is
s = w _o + x · w _x + y · w _y + z · w _z
This is a normalization variable for normalizing the weighting factors w ₁ , w ₂ , w ₃ , and w ₄ .

For example, as the weight of the measurement result of the own radio base station and other radio base stations,
w _o = 1, w _x = 0, w _y = 0.5, w _z = 0.25
As shown in FIG. 39, the total number of other radio base stations that have transmitted the signal strength measurement results to the radio base station 1 is four radio base stations 2, 3, 4, and 5. 38, among the four other radio base stations, two radio base stations 2 and 4 are present, each having a distance from the radio base station 1 within 30 m of the distance threshold Dth, A radio base station whose distance exceeds the distance threshold Dth of 30 m and is within the second distance threshold 50 m is one of the radio base stations 3, and a radio base station whose distance exceeds the second distance threshold 50 m is a radio base station If it is one of the stations 5, the normalization variable s is
s = 1 + 2 × 0 + 1 × 0.5 + 1 × 0.25 = 1.75
It is.

Therefore, the weighting factor w ₁ of the measurement result of the own radio base station is
w ₁ = 1 / 1.75
It is.

Further, the weight coefficient w ₂ of the measurement results of the radio base stations 2 and 4 within 30 m of the distance threshold Dth is
w ₂ = 0 / 1.75
The weight coefficient w ₃ of the measurement result of the radio base station 3 that exceeds the distance threshold Dth of 30 m and is within the second distance threshold 50 m is:
w ₃ = 0.5 / 1.75
The weight coefficient w ₃ of the measurement result of the radio base station 5 exceeding the distance 50 m is
w ₄ = 0.25 / 1.75
It is.

Therefore, in the weight corrector 10eB ₁ in the present embodiment in the case of the numerical example as described above, the weight coefficient w ₁ = 1 for the measurement results of the signal strength of each radio base station shown in FIG. 39, respectively. /1.75, w ₂ = 0 / 1.75, w ₃ = 0.5 / 1.75, and w ₄ = 0.25 / 1.75. That is, as a weighting factor, a numerical value to be multiplied with the measurement results of the radio base stations 1, 2, 3, 4, and 5 can be set to an appropriate arbitrary value, and the distance from the own radio base station 1 can be set. “0” is set for the measured value of the received power at another radio base station existing within 30 m of the threshold Dth. Also, for the measured value of the received power at the other radio base station existing at a location far from the distance threshold Dth of 30 m, a weighting factor is set so as to be inversely proportional to the distance between the own radio base station and the other radio base station. It is set.

  That is, when the other radio base station is farther from the own radio base station 1, the measured value of the received power is “0.5” when exceeding 30 m and within 50 m, and “0.25” when exceeding 50 m. Is multiplied by a small weighting factor. However, the numerical values to be multiplied with the measurement results of the radio base stations 1, 2, 3, 4, and 5 shown as an example here are only examples, and are not limited thereto. For example, the distance threshold Dth may be calculated based on the simulation result of each radio base station, and as a weighting factor for other radio base stations existing in the area exceeding the distance threshold Dth, the own radio base station-other A value inversely proportional to the square of the distance between the radio base stations may be used.

Thereafter, in the adder 10eB ₂ of communication frequency band determiner 10eB, for each band m, the weight coefficient _{w 1, w 2, w 3} , w 4 measuring signal strength of each radio base station which is weighted with the The results are added to calculate a corrected signal strength SP (m) subjected to weight correction. That is, if the power measurement value (measurement result) of the band number m in the radio base station i (i = 1 to 5 in FIG. 39) is P _i (m), each radio base station in the band m in the radio base station 1 The corrected signal strength SP ₁ (m) after weight-correcting and combining the signal strength measurement results P _i (m) of the stations is multiplied by a weight correction value, that is, a weighting factor corresponding to the distance between the radio base stations. As a result, it is given as follows.

SP ₁ (m) = (1 / 1.75) · P ₁ (m) + (0 / 1.75) · P ₂ (m)
+ (0.5 / 1.75) · P ₃ (m) + (0 / 1.75) · P ₄ (m)
+ (0.25 / 1.75) · P ₅ (m) (8)
Here, if the measurement results of the signal strength for each band in each of the radio base stations 1, 2, 3, 4, and 5 are as shown in FIG. 39, the radio base station shown in FIG. The calculation result of the correction signal intensity SP ₁ (m) for each band m in 1 is given as follows.

SP ₁ (1) = (1 / 1.75) · (−86)
+ (0 / 1.75) · (−85)
+ (0.5 / 1.75) ・ (−90)
+ (0 / 1.75) ・ (−88)
+ (0.25 / 1.75) · (−108)
= -90.3dBm
SP ₁ (2) = -100.3 dBm
SP ₁ (3) = − 124.3 dBm
SP ₁ (4) = -128.6 dBm
SP ₁ (5) = -128.3 dBm
SP ₁ (6) = -108.7 dBm
SP ₁ (7) = − 99.3 dBm
SP ₁ (8) = -96.4 dBm
SP ₁ (9) = − 110.4 dBm
SP ₁ (10) = − 116.3 dBm
Next, in the comparator 10eB ₃ of the communication frequency band determiner 10eB, the corrected signal strength SP ₁ (m) after weight correction output from the adder 10eB ₂ is a predetermined threshold value for determining a free frequency, for example, −120 dBm. And a band below the threshold is determined to be empty. Therefore, when the correction signal strength SP ₁ (m) of each band (each frequency band) as described above is obtained based on the measurement result of the signal strength of FIG. 39, the frequency determiner 10eB ₄ performs the comparison. Based on the comparison result (determination result indicating whether or not it is an empty frequency) from the device 10eB ₃ , the band determined to be an empty frequency band is the correction signal intensity SP ₁ (3), SP ₁ (4), SP ₁ (5) Corresponding band numbers 3, 4, and 5 are considered to be vacant frequency bands. Further, among these three bands, it is determined that the band having the lowest correction signal intensity SP ₁ (m) (that is, the band number 4 in the above case) is the band having the smallest amount of interference, and Decide to use the frequency band for communication.

From the calculation results described above, in the frequency determiner 10eB ₄ frequency bands determiner 10eB for communication of the wireless base station 1, regarded as a frequency band band number 4 is free. Accordingly, the frequency determiner 10eB ₄ of the communication frequency band determiner 10eB of the radio base station 1 having the configuration of the radio base station 10B of FIG. 18 starts communication with a center frequency of 2.435 GHz and a bandwidth of 10 MHz of the band number 4. It decides to use for communication with the wireless terminal 30 that has transmitted the request packet, and sets the frequency and bandwidth of the wireless signal processing unit 10h shown in FIG. Further, as shown in the flowchart of FIG. 10, at the same time, the frequency instruction packet storing the frequency / bandwidth information determined to be used for communication of the wireless terminal 30 is stored via the base station-terminal interface unit 10f. The communication start request packet is transmitted to the wireless terminal 30 that is the transmission source (step S14). The wireless terminal 30 receives this frequency instruction packet (step S15), sets the frequency / bandwidth of the wireless signal processing unit 30b shown in FIG. 3, and starts communication.

As described above, as the communication frequency band determiner 10eB, the measurement results of the signal strength of the own radio base station 1 and the measurement results of the signal strengths transmitted from the other radio communication station devices 2, 3, 4, and 5 For all frequency bands to be used, a weight set in advance for each frequency band according to the communication environment of the radio base station (environmental conditions including whether or not under shadowing environment) and the distance between the radio base stations is weight correction using the weight correction means comprising a weight corrector 10eB ₁ performing weighting correction by the adder 10eB ₂ Metropolitan (weight coefficient in this embodiment) correction value, the signal strength of the radio communication station And the measurement result of the signal strength of the other wireless communication station device transmitted from the other wireless communication station device, that is, the correction signal strength SP ₁ (m), is used in advance for determining the free frequency. Compared to determined threshold, the comparator 10eB ₃ for outputting a determination result of the signal strength indicating whether vacant frequency in vicinity of the own radio station apparatus, by providing at least the distance from the radio base station 1 Accordingly, it is possible to perform weight correction of the measurement result of the signal intensity according to the above, and thus, it is possible to obtain a more accurate determination result of the vacant frequency around the own radio communication station apparatus.

More specifically, the radio base station 1 uses not only the signal strength determination result in the radio base station 1 but also the communication environment of the radio base station (for example, signal strength measurement) as the frequency band of the radio signal used for this communication. All other radio base stations 2 located in the vicinity of the own radio base station 1 by performing weight correction according to the distance and the like (environmental condition indicating whether or not under a shadowing environment in which values are correlated) , 3, 4, and 5, the band having a low signal strength below a predetermined threshold value for vacant frequency determination is used for both the self and other wireless base stations. Since the system has been decided to use it as a communication frequency band, even if radio waves from other wireless communication systems are blocked by obstacles or fading, etc. Time manner or not the reception level becomes weak, also, such as radio wave detector 10c bandpass filter 10c ₃ of the error is or generated in the detection precision of an instrument portion of the radio base station for detecting a free frequency Even if there is a case, it is possible to reduce the probability of erroneous detection of free frequencies around the radio base station 1 and to further improve the detection accuracy of free frequencies.

  Here, for the received power measurement value (signal strength measurement value) of another radio base station existing within a predetermined distance threshold Dth as a case in the shadowing environment from the own radio base station 1, “0” is set. By multiplying a weighting factor of “,” the received power measurement values of other radio base stations in the shadowing environment are substantially not reflected for detection of free frequencies. That is, since the received power measurement value of another radio base station having a high correlation with the received power measurement value of the own radio base station 1 is not used for detecting a free frequency, the communication environment of the radio base station 1 is correlated. Even in a shadowing environment, an effect of avoiding interference with other wireless communication systems can be obtained.

  In the above-described embodiment, the signal strength measurement result in the own radio communication station device and the signal strength measurement result in the other radio communication station device transmitted from the other radio communication station device are all used. For the frequency band, for each frequency band, an example in which weight correction is performed using a weight correction value to which a weight coefficient set in advance according to the communication environment of the radio base station and the distance between the radio base stations has been described. However, this is not the only case.

  For example, weight correction is performed on the terminal measurement result of the signal strength measured in one or a plurality of radio terminals existing in the service area of the own radio base station and the terminal measurement result of the signal strength of another radio base station. Alternatively, the average value obtained by averaging the terminal measurement results of signal strength transmitted from one or a plurality of wireless terminals existing in the service area of the own wireless base station, and transmitted from other wireless base stations. The weighted correction may be applied to the added average value. In addition, the weighting is performed in consideration of a change in the communication environment of the radio base station as described in the seventh embodiment (for example, any one or more of installation location, communication time zone, past interference occurrence state, etc.). Corrections may be made. Further, as described in the sixth embodiment, not only the frequency band used for communication but also the communication method and / or transmission power used for communication may be determined.

(Ninth embodiment)
Next, a ninth embodiment relating to a wireless communication system, a wireless communication station apparatus (wireless base station), a wireless terminal apparatus (wireless terminal), and a wireless communication method according to the present invention will be described. In the present embodiment, when performing weight correction on the signal strength measurement results of each radio base station in the communication frequency and communication method determination processing on the radio base station side, as in the case of the eighth embodiment, Unlike the cases of the third and fourth embodiments described above, a case is considered where there is a shadowing environment in which there is a correlation with the received power measurement value of each radio base station existing in the vicinity. In the case where the weight correction is performed in the above, another example different from the case of the eighth embodiment will be described.

  That is, in the present embodiment, the communication frequency and communication method are determined for the wireless base station that exists within the predetermined distance threshold Dth from the wireless base station that determines the communication frequency and communication method. The weighting coefficient is corrected in proportion to the distance instead of “0” in the eighth embodiment, assuming that it is affected by shadowing that causes a correlation with the radio base station regarding the received power measurement value. When the signal strength measurement result of the radio base station existing within the range of the distance threshold Dth is not reflected in the determination process of the communication frequency or the communication method as the other radio base station having a shorter distance as a weighting factor Is shown.

In the present embodiment, as shown in FIG. 40, in the calculation formula of the correction signal strength SP ₁ (m) used when performing the process of detecting the vacant frequency, as shown in FIG. 40, the communication environment (for example, shadowing environment) and the radio base station The value of the weighting factor for correcting the signal strength measurement value is determined according to the distance between them. FIG. 40 is a schematic diagram showing another example different from FIG. 37 of the determination method for determining the value of the weighting coefficient in accordance with the communication environment and the distance between the radio base stations, and exists in such a shadowing environment. The different radio base station and the other radio base station existing outside the shadowing environment show different examples in which the weight coefficient for weight correction of the received power measurement value is determined by different methods.

  In other words, as shown in FIG. 40, the weighting factor for other radio base stations existing within a predetermined distance threshold Dth within the range under the shadowing environment is set to “0” as in the eighth embodiment. Instead, the weight coefficient value for correcting the signal strength is determined in proportion to the distance between the own radio base station and the other radio base station, the distance from the own radio base station is close, The received power measurement values of other radio base stations that are more strongly affected by the in-flight environment are reflected less by the processing for determining the communication frequency and communication method, while they exist within the range exceeding the distance threshold Dth, and shadowing For other radio base stations outside the environment, as in the case of the third embodiment shown in FIG. 36, the weight for correcting the signal strength in inverse proportion to the distance between the own radio base station and the other radio base station. Coefficient value To make determined.

  The system configuration of the wireless communication system in the present embodiment is the same as that of the first embodiment shown in FIG. Further, the configuration of the wireless terminal in this embodiment is the same as that of FIG. 3 of the first embodiment, and the configuration of the wireless base station is the case of FIG. 18 or FIG. 21 of the third or fourth embodiment. It is the same. That is, each of the wireless terminals 31, 32, 33,... Shown in FIG. 1 has the configuration of the wireless terminal 30 shown in FIG. 3, and each of the wireless base stations 1, 2, 3, 4, 5 is for communication in FIG. The radio base station 10B of FIG. 18 provided with the frequency band determiner 10eB or the radio base station 10C of FIG. 21 provided with the communication frequency band determiner 10eC of FIG.

  Note that the distance between the radio base stations is the same as the case of FIG. 38 of the eighth embodiment, unlike the case of FIG. 2 of the first embodiment. Here, when the distance between radio base stations is set to, for example, 30 m as the distance threshold value Dth at which the correlation of the received power measurement value under the shadowing environment will occur, when determining the communication frequency and communication method The received power measurement values of the radio base stations 2 and 4 existing within the distance threshold Dth, for example, 30 m from the radio base station 1, are assumed to be in a shadowing environment, and the weight coefficients are set to the respective values from the radio base station 1. By setting the values in proportion to the distances 30 m and 20 m, the received power measurement value of the radio base station 4 close to the radio base station 1 out of the radio base stations 2 and 4 in the shadowing environment is set to a far radio base. The weighting factor is set so that the degree of influence is lower than that of the received power measurement value of the station 2.

  That is, as shown in the third embodiment, when the received power measurement value (signal strength) is multiplied as a weight correction value, the weights of the radio base stations 2 and 4 in the shadowing environment are When multiplying the coefficient as a small value proportional to the distance from the radio base station 1 and adding / subtracting the propagation loss amount as a weight correction value to the received power measurement value (signal strength) as shown in the fourth embodiment For the radio base stations 2 and 4 in the shadowing environment, the propagation loss is subtracted instead of being added as a value inversely proportional to the distance from the radio base station 1.

  In the following, with respect to the present embodiment using the radio terminal 30 and the radio base station 10B configured as shown in FIGS. 3 and 18, determination of the frequency and bandwidth of the radio signal used for communication in the radio base station 1 shown in FIG. Processing will be described with reference to the flowcharts of FIGS. 7 and 10 showing an example of the wireless communication method of the present invention. The case where the radio base station has the configuration of the radio base station 10B of FIG. 18 will be described below, but the case where the radio base station has the configuration of the radio base station 10C of FIG. Yes, except that when the received power measurement value (signal strength measurement value) of each radio base station is subjected to weight correction, processing for adding / subtracting the propagation loss amount is performed as a weight correction value instead of multiplying by a weight coefficient This is exactly the same as the following description.

  In the present embodiment, in the radio base station 1 of FIG. 1 having the configuration of the radio base station 10B of FIG. 18, as in the first embodiment, the signal of the radio signal is detected in order to detect the free frequency of the radio signal. Two processes are performed: a radio wave detection process for measuring the intensity and a communication start process for performing a series of processes from the determination of the frequency band used for communication to the start of communication. The radio wave detection process is periodically executed at a predetermined cycle, and the communication start process is executed with a communication start request from a communication start request packet from a wireless terminal as a trigger.

  First, an example of radio wave detection processing in the present embodiment of the radio base station 1 having the configuration of the radio base station 10B in FIG. 18 will be described with reference to FIG. The radio wave detection process in the present embodiment of the radio base station 1 for detecting the free frequency of the radio signal is substantially the same as the flowchart of FIG. 7 in the first embodiment.

  In FIG. 7, first, a timer synchronized between all the radio base stations is set to time until a predetermined time period (step S1), and the timer reaches a predetermined time period (no in step S3). Then, the reduction process is performed (step S2), and when the timer expires (yes in step S3), the radio wave detection process is started.

When the radio wave detection process is started in the radio wave detector 10c shown in FIG. 5 provided in the radio base station 10B of FIG. 18, the radio wave detector 10c sets the frequency band 2.4 GHz-2.5 GHz of the candidate for use to 10 MHz. Separate the plurality of bands having a width of (10 bands in the present embodiment), the center frequency of the bandpass filter 10c ₃ is, between the 2.405GHz the center frequency of each band up to 2.495GHz, i.e. Until the measurement of the signal intensity in all frequency bands is completed (no in step S5), the center frequency is sequentially changed by 10 MHz (step S6), and each band of the radio signal received by the radio wave detection antenna 10b is measured. Is measured by the power measuring device 10c ₄ as the signal strength (step S4).

  When the measurement of the signal strength in all frequency bands is completed (yes in step S5), the signal strength measurement result is then transmitted to other radio base stations via the signal lines 21,..., 27 shown in FIG. Are exchanged (step S7). In this embodiment in which the signal strength measurement result is weight-corrected according to the distance between the radio base stations, the radio base station exchanging the signal strength measurement result is the same as the third embodiment. Not only radio base stations existing within a circle with a radius of 5 km centered on the station, but also all radio base stations existing in the vicinity (radio base stations 1, 2, 3, 4, 5 in this embodiment) Further, the information exchanged with other radio base stations is limited to the signal strength measurement result as in the case of the third embodiment, and the determination result comparing the measurement result with a threshold value, for example, -120 dBm. No action to replace.

  Here, in the radio base station 1, the measurement result of the signal strength of the radio base station 1 itself and the signal strength transmitted from each of the radio base stations 2, 3, 4 and 5 existing in the vicinity of the radio base station 1 The measurement result is assumed to be as shown in FIG. 39 as in the case of the eighth embodiment.

  The measurement result of the signal strength as shown in FIG. 39 is input to the communication frequency band determiner 10eB in FIG. In the communication frequency band determiner 10eB, based on the signal strength measurement results in the plurality of radio base stations of the own radio base station 1 and the other radio base stations 2, 3, 4 and 5, the surroundings of the radio base station 1 In this step, a free frequency band that is not currently used is extracted, and a free frequency band that is used for the current communication by the wireless terminal that is the transmission start request packet is determined.

  Next, in the present embodiment of the radio base station 1 having the configuration of the radio base station 10B of FIG. In this embodiment, the flowchart of the radio base station 1 that performs the communication start process of the radio terminal 30 is almost the same as that in FIG.

  First, the wireless terminal having the configuration of the wireless terminal 30 of FIG. 3 and requesting the start of communication sends a communication start request packet to the wireless base station of FIG. 18 via the base station-terminal interface unit 30d of FIG. It transmits with respect to the wireless base station 1 which consists of a structure of 10B (step S11). When the radio base station 1 receives the communication start request packet from the radio terminal 30 via the radio base station-terminal interface unit 10f in FIG. 18 (step S12), the radio frequency base station 10eB performs the radio communication. The determination process of the frequency band used by the terminal 30 for the current communication is performed according to the following procedure (step S13).

In the communication frequency band determiner 10eB of the radio base station 1 having the configuration of the radio base station 10B of FIG. 18, first, in the weight corrector 10eB ₁ shown in FIG. 19, the signal strength of each radio base station shown in FIG. The measurement result is multiplied by a weight coefficient as a weight correction value. Here, the weighting coefficient to be multiplied as the weight correction value is determined between the communication environment (for example, an environmental condition indicating whether or not a shadowing environment in which a correlation is generated in the received power measurement value of the wireless base station) and between the wireless base stations. It is determined according to the distance.

For example, among the other radio base stations that have transmitted the measurement result weight w _o and the signal strength measurement result of the own radio base station, the distance from the own radio base station is within 20 m in the very vicinity in the shadowing environment. The total number v of the other radio base stations existing, the weight w _v of each measurement result of the other radio base station, the distance threshold Dth that is predetermined as being in the shadowing environment exceeding 20 m in the very near range, for example, within 30 m The total number x of the other radio base stations existing, the weight w _x of each measurement result of the other radio base station, and the other radio bases within the second distance threshold 50 m that are predetermined in advance with the distance from the own radio base station exceeding 30 m When the total number y of stations and the weight w _y of each measurement result of the other radio base station are set, the total number z of other radio base stations exceeding 50 m and the weight w _z of each measurement result of the other radio base station, Street, It is determined according to the distance between the radio base stations.

That is, the weighting factor w ₁ of the measurement result of the own radio base station is
w ₁ = w _o / s
Given in.

Further, the weight coefficient w ₂ of each of the other radio base station of the measurement results of the circle of radius 20m around the radio base station,
w ₂ = w _v / s
Given the weighting factor w ₃ of each of the other radio base station of the measurement results of the circle of radius 30m beyond the radius 20m around the radio base station is,
w ₃ = w _x / s
The weight coefficient w ₄ of the measurement result of each of the other radio base stations in a circle having a radius of more than 30 m and a radius of 50 m centered on the own radio base station is
w ₄ = w _y / s
The weight coefficient w ₅ of the measurement result of each of the other radio base stations outside the circle with a radius of 50 m centered on the own radio base station is
w ₅ = w _z / s
Given in.

Here, the variable s is
s = w _o + v · w _v + x · w _x + y · w _y + z · w _z
This is a normalization variable for normalizing the weighting factors w ₁ , w ₂ , w ₃ , w ₄ , w ₅ .

For example, as the weight of the measurement result of the own radio base station and other radio base stations,
w _o = 1, w _v = 0, w _x = 0.25, w _y = 0.5, w _z = 0.25
As shown in FIG. 39, the total number of other radio base stations that have transmitted the signal strength measurement results to the radio base station 1 is four radio base stations 2, 3, 4, and 5. 38, among the four other radio base stations, a radio base station that is in the immediate vicinity within 20 m from the radio base station 1 is one of the radio base stations 4, a radio base station A radio base station whose distance from 1 exceeds 20 m and is within 30 m of the distance threshold Dth is one of the radio base stations 2 and whose distance exceeds 30 m of the distance threshold Dth and is within the second distance threshold 50 m If the radio base station is one of the radio base stations 3 and the radio base station whose distance exceeds the second distance threshold 50 m is one of the radio base stations 5, the normalization variable s is
s = 1 + 1 × 0.25 + 1 × 0.5 + 1 × 0 + 1 × 0.25 = 2.0
It is.

Therefore, the weighting factor w ₁ of the measurement result of the own radio base station is
w ₁ = 1 / 2.0
It is.

Further, the weight coefficient w ₂ of the measurement result of the radio base station 4 within a radius of 20 m is
w ₂ = 0 / 2.0
Further, the weight coefficient w ₃ of the measurement result of the radio base station 2 that exceeds the radius 20 m and is within 30 m of the distance threshold Dth is:
w ₃ = 0.25 / 2.0
The weight coefficient w ₄ of the measurement result of the radio base station 3 that exceeds the distance threshold Dth of 30 m and is within the second distance threshold 50 m is:
w ₄ = 0.5 / 2.0
The weight coefficient w ₅ of the measurement result of the radio base station 5 exceeding the distance 50 m is
w ₅ = 0.25 / 2.0
It is.

Therefore, in the weight corrector 10eB ₁ in the present embodiment in the case of the numerical example as described above, the weight coefficient w ₁ = 1 for the measurement results of the signal strength of each radio base station shown in FIG. 39, respectively. /2.0, w ₂ = 0 / 2.0, w ₃ = 0.25 / 2.0, w ₄ = 0.5 / 2.0, w ₅ = 0.25 / 2.0. To. That is, as a weighting factor, a numerical value to be multiplied with the measurement results of the radio base stations 1, 2, 3, 4, and 5 can be set to an appropriate arbitrary value, and the distance from the own radio base station 1 can be set. The measured value of the received power at the other radio base station existing within 30 m of the threshold value Dth is proportional to the distance between the own radio base station and the other radio base station, and is just from the own radio base station 1. The weighting factor is set so that the weighting factor in the other radio base station existing at the distance threshold Dth of 30 m is larger than that of the other radio base station existing in the range exceeding the distance threshold Dth of 30 m.

  That is, “0” is set for the measured value of the received power at other radio base stations in the vicinity of, for example, within 20 m, and the received power at other radio base stations existing within 30 m of the distance threshold Dth exceeding 20 m. “0.25” is set for the measured value. Also, for the measured value of the received power at the other radio base station existing at a location far from the distance threshold Dth of 30 m, a weighting factor is set so as to be inversely proportional to the distance between the own radio base station and the other radio base station. It is set. That is, when the other radio base station is farther from the own radio base station 1, the measured value of the received power is “0.5” when exceeding 30 m and within 50 m, and “0.25” when exceeding 50 m. Is multiplied by a small weighting factor.

  However, the numerical values to be multiplied with the measurement results of the radio base stations 1, 2, 3, 4, and 5 shown as an example here are only examples, and are not limited thereto. For example, the distance threshold Dth may be calculated based on the simulation result of each radio base station. For other radio base stations that are within 30 m of the distance threshold Dth in the shadowing environment, the own radio base station-other A weighting factor proportional to the square of the distance between the radio base stations, and for other radio base stations existing in an area exceeding the distance threshold Dth of 30 m, is inversely proportional to the square of the distance between the own radio base station and the other radio base station. It is good also as a weighting coefficient to do.

Thereafter, in the adder 10eB ₂ of communication frequency band determiner 10eB, for each band m, the weight coefficient _{w 1, w 2, w 3} , w 4, the signal of each radio base station weighted with _{w 5} By adding the intensity measurement results, a corrected signal intensity SP (m) subjected to weight correction is calculated. That is, if the power measurement value (measurement result) of the band number m in the radio base station i (i = 1 to 5 in FIG. 39) is P _i (m), each radio base station in the band m in the radio base station 1 The corrected signal strength SP ₁ (m) after weight-correcting and combining the signal strength measurement results P _i (m) of the stations is multiplied by a weight correction value, that is, a weighting factor corresponding to the distance between the radio base stations. As a result, it is given as follows.

SP ₁ (m) = (1 / 2.0) · P ₁ (m) + (0.25 / 2.0) · P ₂ (m)
+ (0.5 / 2.0) · P ₃ (m) + (0 / 2.0) · P ₄ (m)
+ (0.25 / 2.0) · P ₅ (m) (9)
Here, if the measurement results of the signal strength for each band in each of the radio base stations 1, 2, 3, 4, and 5 are as shown in FIG. 39, the radio base station shown in FIG. The calculation result of the correction signal intensity SP ₁ (m) for each band m in 1 is given as follows.

SP ₁ (1) = (1 / 2.0) · (−86)
+ (0.25 / 2.0) · (−85)
+ (0.5 / 2.0) ・ (−90)
+ (0 / 2.0) ・ (-88)
+ (0.25 / 2.0) · (−108)
= -89.6 dBm
SP ₁ (2) = -100.5 dBm
SP ₁ (3) = -125.8 dBm
SP ₁ (4) = -129.5 dBm
SP ₁ (5) = -129.0 dBm
SP ₁ (6) = -107.3 dBm
SP ₁ (7) = − 97.4 dBm
SP ₁ (8) = − 95.1 dBm
SP ₁ (9) = -108.8 dBm
SP ₁ (10) = − 115.4 dBm
Next, in the comparator 10eB ₃ of the communication frequency band determiner 10eB, the corrected signal strength SP ₁ (m) after weight correction output from the adder 10eB ₂ is a predetermined threshold value for determining a free frequency, for example, −120 dBm. And a band below the threshold is determined to be empty. Therefore, when the correction signal strength SP ₁ (m) of each band (each frequency band) as described above is obtained based on the measurement result of the signal strength of FIG. 39, the frequency determiner 10eB ₄ performs the comparison. Based on the comparison result (determination result indicating whether or not it is an empty frequency) from the device 10eB ₃ , the band determined to be an empty frequency band is the correction signal intensity SP ₁ (3), SP ₁ (4), SP ₁ (5). Corresponding band numbers 3, 4, and 5 are considered to be vacant frequency bands. Further, among these three bands, it is determined that the band having the lowest correction signal intensity SP ₁ (m) (that is, the band number 4 in the above case) is the band having the smallest amount of interference, and Decide to use the frequency band for communication.

From the calculation results described above, in the frequency determiner 10eB ₄ frequency bands determiner 10eB for communication of the wireless base station 1, regarded as a frequency band band number 4 is free. Accordingly, the frequency determiner 10eB ₄ of the communication frequency band determiner 10eB of the radio base station 1 having the configuration of the radio base station 10B of FIG. 18 starts communication with a center frequency of 2.435 GHz and a bandwidth of 10 MHz of the band number 4. It decides to use for communication with the wireless terminal 30 that has transmitted the request packet, and sets the frequency and bandwidth of the wireless signal processing unit 10h shown in FIG. Further, as shown in the flowchart of FIG. 10, at the same time, the frequency instruction packet storing the frequency / bandwidth information determined to be used for communication of the wireless terminal 30 is stored via the base station-terminal interface unit 10f. The communication start request packet is transmitted to the wireless terminal 30 that is the transmission source (step S14). The wireless terminal 30 receives this frequency instruction packet (step S15), sets the frequency / bandwidth of the wireless signal processing unit 30b shown in FIG. 3, and starts communication.

As described above, as the communication frequency band determiner 10eB, the measurement results of the signal strength of the own radio base station 1 and the measurement results of the signal strengths transmitted from the other radio communication station devices 2, 3, 4, and 5 For all frequency bands to be used, a weight set in advance for each frequency band according to the communication environment of the radio base station (environmental conditions including whether or not under shadowing environment) and the distance between the radio base stations is weight correction using the weight correction means comprising a weight corrector 10eB ₁ performing weighting correction by the adder 10eB ₂ Metropolitan (weight coefficient in this embodiment) correction value, the signal strength of the radio communication station And the measurement result of the signal strength of the other wireless communication station device transmitted from the other wireless communication station device, that is, the correction signal strength SP ₁ (m), is used in advance for determining the free frequency. Compared to determined threshold, the comparator 10eB ₃ for outputting a determination result of the signal strength indicating whether vacant frequency in vicinity of the own radio station apparatus, by providing at least the distance from the radio base station 1 Accordingly, it is possible to perform weight correction of the measurement result of the signal intensity according to the above, and thus, it is possible to obtain a more accurate determination result of the vacant frequency around the own radio communication station apparatus.

More specifically, the radio base station 1 uses not only the signal strength determination result in the radio base station 1 but also the communication environment of the radio base station (for example, signal strength measurement) as the frequency band of the radio signal used for this communication. All other radio base stations 2 located in the vicinity of the own radio base station 1 by performing weight correction according to the distance and the like (environmental condition indicating whether or not under a shadowing environment in which values are correlated) , 3, 4, and 5, the band having a low signal strength below a predetermined threshold value for vacant frequency determination is used for both the self and other wireless base stations. Since the system has been decided to use it as a communication frequency band, even if radio waves from other wireless communication systems are blocked by obstacles or fading, etc. Time manner or not the reception level becomes weak, also, such as radio wave detector 10c bandpass filter 10c ₃ of the error is or generated in the detection precision of an instrument portion of the radio base station for detecting a free frequency Even if there is a case, it is possible to reduce the probability of erroneous detection of free frequencies around the radio base station 1 and to further improve the detection accuracy of free frequencies.

  Here, from the own radio base station 1 to the received radio power measurement value (signal strength measurement value) of another radio base station existing within a predetermined distance threshold Dth as being in the shadowing environment By multiplying the weighting factor proportional to the distance between the base station 1 and the other radio base station, the closer to the own radio base station 1, the smaller the weighting factor is multiplied with the received power measurement value at the other radio base station. Therefore, for the detection of the vacant frequency, the influence of the received power measurement value can be substantially reduced as the other radio base station has a higher correlation in the shadowing environment. That is, when detecting the free frequency in the own radio base station 1, the degree of influence of the received power measurement values of other radio base stations according to the degree of correlation with the received power measurement value of the own radio base station 1 is high. Therefore, even if the communication environment of the radio base station 1 is in a correlated shadowing environment, an effect of avoiding interference with other radio communication systems can be obtained.

  In the above-described embodiment, the signal strength measurement result in the own radio communication station device and the signal strength measurement result in the other radio communication station device transmitted from the other radio communication station device are all used. For the frequency band, for each frequency band, an example in which weight correction is performed using a weight correction value to which a weight coefficient set in advance according to the communication environment of the radio base station and the distance between the radio base stations has been described. However, this is not the only case.

  For example, weight correction is performed on the terminal measurement result of the signal strength measured in one or a plurality of radio terminals existing in the service area of the own radio base station and the terminal measurement result of the signal strength of another radio base station. Alternatively, the average value obtained by averaging the terminal measurement results of signal strength transmitted from one or a plurality of wireless terminals existing in the service area of the own wireless base station, and transmitted from other wireless base stations. The weighted correction may be applied to the added average value. In addition, the weighting is performed in consideration of a change in the communication environment of the radio base station as described in the seventh embodiment (for example, any one or more of installation location, communication time zone, past interference occurrence state, etc.). Corrections may be made. Further, as described in the sixth embodiment, not only the frequency band used for communication but also the communication method and / or transmission power used for communication may be determined.

1 is a system configuration diagram illustrating an example of a system configuration of a wireless communication system according to the present invention. It is explanatory drawing which shows an example of the distance between a certain wireless base station shown in FIG. 1, and other nearby wireless base stations. It is a block block diagram which shows an example of the block configuration of the radio | wireless terminal in 1st Example of this invention. It is a block block diagram which shows an example of the block configuration of the radio base station in the 1st Example of this invention. FIG. 5 is a block configuration diagram illustrating an example of a block configuration of a radio wave detector of the radio base station illustrated in FIG. 4. FIG. 5 is a block configuration diagram illustrating an example of a configuration of a communication frequency band determiner of the radio base station illustrated in FIG. 4. It is a flowchart which shows an example of the electromagnetic wave detection process in each radio | wireless base station of 1st Example of this invention. It is explanatory drawing at the time of assigning a band number for every 10 MHz in a 2.4 GHz-2.5 GHz band. In the 1st Example of this invention, it is a table which shows the measurement result and determination result of the electric power for every band number in each wireless base station shown in FIG. It is a flowchart which shows an example of the operation | movement which performs the communication start process of a radio | wireless terminal in the radio base station of 1st Example of this invention. It is a block block diagram which shows an example of the block configuration of the radio | wireless terminal in 2nd Example of this invention. It is a block block diagram which shows an example of the block configuration of the radio base station in the 2nd Example of this invention. It is a block block diagram which shows an example of a structure of the communication frequency band determination device of the wireless base station shown in FIG. It is a flowchart which shows an example of the electromagnetic wave detection process in each radio | wireless terminal of 2nd Example of this invention. In the 2nd Example of this invention, it is a table which shows the terminal measurement result of the electric power for every band number in each radio | wireless terminal which exists in the service area of the radio base station which received the communication start request | requirement from the radio | wireless terminal. In the 2nd Example of this invention, it is a table which shows the terminal determination result of the electric power for every band number in each radio | wireless terminal which exists in the service area of the radio base station which received the communication start request | requirement from the radio | wireless terminal. It is a table which shows the determination result of the electric power for every band number in the other radio base station adjacent to the radio base station which received the communication start request from the radio terminal. It is a block block diagram which shows an example of the block configuration of the radio base station in the 3rd Example of this invention. It is a block block diagram which shows an example of a structure of the communication frequency band determination device of the wireless base station shown in FIG. In the 3rd Example of this invention, it is a table which shows the measurement result of the electric power for every band number in each radio base station shown in FIG. It is a block block diagram which shows an example of the block configuration of the radio base station in the 4th Example of this invention. It is a block block diagram which shows an example of a structure of the communication frequency band determination device of the wireless base station shown in FIG. In the 4th Example of this invention, it is a table which shows the measurement result of the electric power for every band number in each radio base station shown in FIG. In the 4th Example of this invention, it is a table | surface which shows the correction | amendment measurement result and determination result which correct | amended the measurement result of the electric power for every band number in each radio base station shown in FIG. It is a block block diagram which shows an example of the block configuration of the radio | wireless terminal in the 5th Example of this invention. It is a block block diagram which shows an example of the block configuration of the radio base station in the 5th Example of this invention. FIG. 27 is a block configuration diagram showing an example of a configuration of a communication frequency band determiner of the radio base station shown in FIG. 26. It is a flowchart which shows an example of the electromagnetic wave detection process in each radio | wireless terminal of the 5th Example of this invention. It is a block block diagram which shows an example of the block configuration of the radio | wireless terminal in the 6th Example of this invention. It is a block block diagram which shows an example of the block configuration of the radio base station in the 6th Example of this invention. FIG. 31 is a block configuration diagram showing an example of a configuration of a communication frequency band / communication method determiner of the radio base station shown in FIG. 30. It is a flowchart which shows an example of the operation | movement which performs the communication start process of a radio | wireless terminal in the radio base station of the 6th Example of this invention. 10 is a table showing a specific example of a corrected measurement result, that is, a corrected signal intensity obtained by correcting a power measurement result for each band number in the radio base station shown in FIG. 1 in the sixth embodiment of the present invention. In the 6th Example of this invention, it is a table which shows an example of the communication system corresponding to the value of correction | amendment signal strength, and transmission electric energy. It is a correlation diagram which shows the mode of the change of the correlation coefficient of the received power measurement value in each radio station with respect to the distance between radio stations (radio base station, radio terminal). In the 3rd Example of this invention, it is a schematic diagram which shows an example of the determination method which determines the value of a weighting coefficient according to the distance between radio base stations. In the 8th Example of this invention, it is a schematic diagram which shows an example of the determination method which determines the value of a weighting coefficient according to a communication environment and the distance between radio base stations. It is explanatory drawing which shows the other example different from FIG. 2 of the distance between a certain wireless base station shown in FIG. 1, and other nearby wireless base stations. In the 8th Example of this invention, it is a table | surface which shows the correction | amendment measurement result and determination result which correct | amended the measurement result of the electric power for every band number in each wireless base station shown in FIG. FIG. 38 is a schematic diagram showing another example different from FIG. 37 of the determination method for determining the value of the weighting coefficient according to the communication environment and the distance between the radio base stations in the ninth embodiment of the present invention.

Explanation of symbols

1, 2, 3, 4, 5, 10, 10A, 10B, 10C, 10D, 10E ... wireless base station, 10a ... communication antenna, 10b ... radio wave detection antenna, 10c ... radio wave detector, 10c ₁ ... orthogonal demodulation 10c ₂ ... synthesizer, 10c ₃ ... band pass filter, 10c ₄ ... power measuring instrument, 10d ... inter-base station interface unit, 10e, 10eA, 10eB, 10eC, 10eD ... communication frequency band determiner, 10e ₁ ... comparison 10e ₂ , 10eA ₁ ... AND operator, 10e ₃ , 10eA ₂ ... frequency determiner, 10eB ₁ ... weight corrector, 10eB ₂ ... adder, 10eB ₃ ... comparator, 10eB ₄ ... frequency determiner, 10eC ₁ ... weight corrector, 10EC 2 _... comparator, 10EC 3 _... AND operation unit, 10EC 4 _... frequency determiner, 10ED ₁ Average calculator, 10eD 2 _... comparator, 10eD 3 _... frequency determiner, 10EE ... frequency band and communication scheme determining apparatus for communication, 10eE 4 _... frequency band and communication scheme determining apparatus, 10f ... base station - terminal between the interface unit, 10 fE ... base station-terminal interface unit, 10 g ... switch, 10 h ... radio signal processing unit, 10 hE ... radio signal processing unit, 11, 12, 13, 14, 15 ... service area 21, 22, 23, 24, 25 , 26, 27 ... signal lines, 30, 30A, 31, 32, 33, 30D, 30E ... wireless terminals, 30a ... antennas, 30b, 30bE ... wireless signal processing units, 30c ... switches (switch 1), 30d, 30dE ... Base station-terminal interface unit, 30e ... radio wave detector, 30f ... comparator, 30g ... switch 2, 100 ... wireless communication system .

Claims (15)

In a wireless communication system comprising a plurality of wireless communication station devices that communicate with one or more wireless terminal devices existing in a service area using wireless signals in a frequency band assigned at the start of communication,
The wireless communication station device
Signal strength measuring means for measuring the signal strength of a radio signal existing around the radio communication station apparatus for all frequency bands to be used; and
Use frequency determining means for determining a frequency band of a radio signal used for communication with the wireless terminal device;
A communication means for transmitting and receiving information to and from each other between a plurality of wireless communication station apparatuses,
While transmitting the measurement result of the signal strength of the radio signal measured by the signal strength measurement means to the other radio communication station apparatus by the communication means,
A signal strength measurement result of a radio signal transmitted from another radio communication station apparatus is received by the communication means, and is measured by the signal strength measurement means of the own radio communication station apparatus by the use frequency determining means. On the basis of the measurement result of the signal strength and the measurement result of the signal strength transmitted from another wireless communication station device received by the communication means, a wireless signal exists in the vicinity of the own wireless communication station device. A wireless communication system that determines whether or not there is a free frequency, and determines a frequency band of a wireless signal to be used for communication with the wireless terminal device according to a determination result determined as a free frequency ,
The use frequency determining means includes
The measurement result of the signal strength measured by the own radio communication station device and the measurement result of the signal strength of the other radio communication station device transmitted from the other radio communication station device, for all frequency bands to be used, for each frequency band A weight correction means for performing weight correction by a preset weight correction value;
The measurement result of the signal strength of the own radio communication station apparatus and the measurement result of the signal intensity of the other radio communication station apparatus transmitted from the other radio communication station apparatus that have been subjected to the weight correction by the weight correction means A determination means for outputting a signal strength determination result indicating whether or not the frequency is an empty frequency compared with a predetermined threshold as
An arithmetic means for performing an operation for determining whether or not the signal strength of the own radio communication station apparatus and other radio communication station apparatus is an empty frequency around the own radio communication station apparatus;
Comprising at least
The weight correction value set in advance in the weight correction means is
Distance between wireless communication station devices, degree of correlation of received signal strength between wireless communication station devices, installation location of wireless communication station device, communication time zone of wireless communication station device, interference in past communication of wireless communication station device A wireless communication system characterized by being determined according to any one or a plurality of occurrence history information . In a wireless communication system comprising a plurality of wireless communication station devices that communicate with one or more wireless terminal devices existing in a service area using wireless signals in a frequency band assigned at the start of communication,
The wireless terminal device
A signal strength measuring means for measuring the signal strength of a wireless signal existing around the wireless terminal device for all frequency bands to be used as a terminal measurement result of the signal strength;
A terminal side transmitting / receiving means for transmitting / receiving information to / from the wireless communication station apparatus in the service area in which the wireless terminal apparatus exists;
The wireless communication station device
Station device side transmitting / receiving means for transmitting / receiving information to / from one or more of the wireless terminal devices existing in the service area of the wireless communication station device;
Use frequency determining means for determining a frequency band of a radio signal used for communication with the wireless terminal device;
A communication means for transmitting and receiving information to and from each other between a plurality of wireless communication station apparatuses,
The wireless terminal device transmits a terminal measurement result of the signal strength measured by the signal strength measuring means to the wireless communication station device by the terminal-side transmitting / receiving means,
The radio communication station apparatus receives terminal measurement results of the signal strength transmitted from one or a plurality of the radio terminal apparatuses existing in a service area of the radio communication station apparatus by the station apparatus side transmitting / receiving means. , While transmitting to another wireless communication station device by the communication means,
The terminal measurement result of the signal strength transmitted from another radio communication station apparatus is received by the communication means and received by the station apparatus side transmitting / receiving means of the own radio communication station apparatus by the use frequency determining means. Based on the terminal measurement result of the signal strength and the terminal measurement result of the signal strength transmitted from another wireless communication station device received by the communication means, a wireless signal exists in the vicinity of the own wireless communication station device. A wireless communication system that determines whether or not a free frequency is determined, and determines a frequency band of a wireless signal to be used for communication with the wireless terminal device according to a determination result determined as a free frequency ,
The use frequency determining means includes
The terminal measurement result of the signal strength of the own radio communication station device and the terminal measurement result of the signal strength of the other radio communication station device are obtained by weight correction values set in advance for each frequency band for all frequency bands to be used. Weight correction means for performing weight correction;
The terminal measurement result of the signal strength of the own radio communication station apparatus and the terminal measurement result of the signal intensity of the other radio communication station apparatus, which have been weight-corrected by the weight correction unit, are compared with a predetermined threshold value for vacant frequency determination. A determination means for outputting a determination result of the signal strength indicating whether or not the frequency is empty;
An arithmetic means for performing an operation for determining whether or not the signal strength of the own radio communication station apparatus and other radio communication station apparatus is an empty frequency around the own radio communication station apparatus;
Comprising at least
The weight correction value set in advance in the weight correction means is
Distance between wireless communication station devices, degree of correlation of received signal strength between wireless communication station devices, installation location of wireless communication station device, communication time zone of wireless communication station device, interference in past communication of wireless communication station device A wireless communication system characterized by being determined according to any one or a plurality of occurrence history information . In a wireless communication system comprising a plurality of wireless communication station devices that communicate with one or more wireless terminal devices existing in a service area using wireless signals in a frequency band assigned at the start of communication,
The wireless terminal device
A signal strength measuring means for measuring the signal strength of a wireless signal existing around the wireless terminal device for all frequency bands to be used as a terminal measurement result of the signal strength;
Terminal-side transmission / reception means for transmitting / receiving information to / from the wireless communication station apparatus in the service area in which the wireless terminal apparatus exists;
With at least
The wireless terminal device transmits a terminal measurement result of the signal strength measured by the signal strength measuring means to the wireless communication station device by the terminal-side transmitting / receiving means,
The wireless communication station device
Station device side transmitting / receiving means for transmitting / receiving information to / from one or more of the wireless terminal devices existing in the service area of the wireless communication station device;
Use frequency determining means for determining a frequency band of a radio signal used for communication with the wireless terminal device;
A communication means for transmitting and receiving information between a plurality of wireless communication station devices;
With at least
In addition, before Symbol use frequency determining means,
A terminal measurement result of the signal strength transmitted from one or more of the wireless terminal devices existing in the service area of the wireless communication station device , received by the station device side transmission / reception means , is used for all frequency bands to be used. For each frequency band, an average calculating means for calculating an average value corresponding to the measurement result of the signal strength in the own radio communication station device by averaging
With at least
The wireless communication station device
While transmitting the average value calculated by the average calculating means, by the pre-Symbol communication means, to other wireless communication station,
The average value that has been transmitted from another wireless communication station receives the previous SL communication means, by the use frequency determining means, the average value of the radio communication station and another wireless communication station Further, the result of addition averaging is compared with a predetermined threshold value for determining a free frequency, and it is determined whether or not a free frequency in which no radio signal exists in the vicinity of the own wireless communication station device. A wireless communication system for determining a frequency band of a wireless signal used for communication with the wireless terminal device based on the determination result,
The use frequency determining means includes
The addition average value of the own radio communication station apparatus calculated by the average calculation means and the addition average value of the other radio communication station apparatus received by the communication means are preliminarily determined for each frequency band for all frequency bands to be used. Weight correction means for performing weight correction by the set weight correction value;
The result obtained by further adding the addition average value of the own radio communication station apparatus and the addition average value of the other radio communication station apparatus that have been subjected to the weight correction by the weight correction unit is compared with a threshold value that is determined in advance for vacant frequency determination. Determination means for outputting a determination result of the signal strength indicating whether or not the frequency is empty,
An arithmetic means for performing an operation for determining whether or not the signal strength of the own radio communication station apparatus and other radio communication station apparatus is an empty frequency around the own radio communication station apparatus;
Comprising at least
The weight correction value set in advance in the weight correction means is
Distance between wireless communication station devices, degree of correlation of received signal strength between wireless communication station devices, installation location of wireless communication station device, communication time zone of wireless communication station device, interference in past communication of wireless communication station device A wireless communication system characterized by being determined according to any one or a plurality of occurrence history information . In a wireless communication station apparatus that performs communication using a wireless signal in a frequency band assigned at the start of communication with one or more wireless terminal apparatuses existing in a service area,
Signal strength measuring means for measuring the signal strength of a radio signal existing around the radio communication station apparatus for all frequency bands to be used; and
Use frequency determining means for determining a frequency band of a radio signal used for communication with the wireless terminal device;
A communication means for transmitting and receiving information to and from each other between a plurality of wireless communication station apparatuses,
While transmitting the measurement result of the signal strength of the radio signal measured by the signal strength measurement means to the other radio communication station apparatus by the communication means,
A signal strength measurement result of a radio signal transmitted from another radio communication station apparatus is received by the communication means, and is measured by the signal strength measurement means of the own radio communication station apparatus by the use frequency determining means. On the basis of the measurement result of the signal strength and the measurement result of the signal strength transmitted from another wireless communication station device received by the communication means, a wireless signal exists in the vicinity of the own wireless communication station device. It is a wireless communication station apparatus that determines whether or not there is a free frequency, and determines a frequency band of a wireless signal used for communication with the wireless terminal device according to a determination result determined as a free frequency ,
The use frequency determining means includes
The measurement result of the signal strength measured by the own radio communication station device and the measurement result of the signal strength of the other radio communication station device transmitted from the other radio communication station device, for all frequency bands to be used, for each frequency band A weight correction means for performing weight correction by a preset weight correction value;
The measurement result of the signal strength of the own radio communication station apparatus and the measurement result of the signal intensity of the other radio communication station apparatus transmitted from the other radio communication station apparatus that have been subjected to the weight correction by the weight correction means A determination means for outputting a signal strength determination result indicating whether or not the frequency is an empty frequency compared with a predetermined threshold as
An arithmetic means for performing an operation for determining whether or not the signal strength of the own radio communication station apparatus and other radio communication station apparatus is an empty frequency around the own radio communication station apparatus;
Comprising at least
The weight correction value set in advance in the weight correction means is
Distance between wireless communication station devices, degree of correlation of received signal strength between wireless communication station devices, installation location of wireless communication station device, communication time zone of wireless communication station device, interference in past communication of wireless communication station device A wireless communication station apparatus, characterized by being determined according to any one or a plurality of occurrence history information . In a wireless communication station apparatus that performs communication using a wireless signal in a frequency band assigned at the start of communication with one or more wireless terminal apparatuses existing in a service area,
Station device side transmitting / receiving means for transmitting / receiving information to / from one or more of the wireless terminal devices existing in the service area of the wireless communication station device;
Use frequency determining means for determining a frequency band of a radio signal used for communication with the wireless terminal device;
A communication means for transmitting and receiving information to and from each other between a plurality of wireless communication station apparatuses,
When the terminal measurement result of the signal strength of the radio signal existing around the wireless terminal device is transmitted from one or a plurality of the wireless terminal devices existing in the service area of the wireless communication station device, the station device side transmission / reception While receiving by means and transmitting to other wireless communication station apparatus by the communication means,
The terminal measurement result of the signal strength transmitted from another radio communication station apparatus is received by the communication means and received by the station apparatus side transmitting / receiving means of the own radio communication station apparatus by the use frequency determining means. Based on the terminal measurement result of the signal strength and the terminal measurement result of the signal strength transmitted from another wireless communication station device received by the communication means, a wireless signal exists in the vicinity of the own wireless communication station device. It is a wireless communication station apparatus that determines whether or not a free frequency is determined, and determines a frequency band of a wireless signal used for communication with the wireless terminal device according to a determination result determined as a free frequency ,
The use frequency determining means includes
The terminal measurement result of the signal strength of the own radio communication station device and the terminal measurement result of the signal strength of the other radio communication station device are obtained by weight correction values set in advance for each frequency band for all frequency bands to be used. Weight correction means for performing weight correction;
The terminal measurement result of the signal strength of the own radio communication station apparatus and the terminal measurement result of the signal intensity of the other radio communication station apparatus, which have been weight-corrected by the weight correction unit, are compared with a predetermined threshold value for vacant frequency determination. A determination means for outputting a determination result of the signal strength indicating whether or not the frequency is empty;
An arithmetic means for performing an operation for determining whether or not the signal strength of the own radio communication station apparatus and other radio communication station apparatus is an empty frequency around the own radio communication station apparatus;
Comprising at least
The weight correction value set in advance in the weight correction means is
Distance between wireless communication station devices, degree of correlation of received signal strength between wireless communication station devices, installation location of wireless communication station device, communication time zone of wireless communication station device, interference in past communication of wireless communication station device A wireless communication station apparatus, characterized by being determined according to any one or a plurality of occurrence history information . In a wireless communication station apparatus that performs communication using a wireless signal in a frequency band assigned at the start of communication with one or more wireless terminal apparatuses existing in a service area,
Station device side transmitting / receiving means for transmitting / receiving information to / from one or more of the wireless terminal devices existing in the service area of the wireless communication station device;
Use frequency determining means for determining a frequency band of a radio signal used for communication with the wireless terminal device;
A communication means for transmitting and receiving information between a plurality of wireless communication station devices;
With at least
Further, the use frequency determining means includes
A terminal measurement result of the signal strength transmitted from one or more of the wireless terminal devices existing in the service area of the wireless communication station device , received by the station device side transmission / reception means , is used for all frequency bands to be used. For each frequency band, an average calculating means for calculating an average value corresponding to the measurement result of the signal strength in the own radio communication station device by averaging
With at least
The average value calculated by the average calculating means, by the communication unit, while transmitting the other radio communication station,
The average value that has been transmitted from another wireless communication station receives the previous SL communication means, by the use frequency determining means, the average value of the radio communication station and another wireless communication station Further, the result of addition averaging is compared with a predetermined threshold value for determining a free frequency, and it is determined whether or not a free frequency in which no radio signal exists in the vicinity of the own wireless communication station device. According to the determination result, a radio communication station apparatus that determines a frequency band of a radio signal used for communication with the radio terminal apparatus,
The use frequency determining means includes
The addition average value of the own radio communication station apparatus calculated by the average calculation means and the addition average value of the other radio communication station apparatus received by the communication means are preliminarily determined for each frequency band for all frequency bands to be used. Weight correction means for performing weight correction by the set weight correction value;
The result obtained by further adding the addition average value of the own radio communication station apparatus and the addition average value of the other radio communication station apparatus that have been subjected to the weight correction by the weight correction unit is compared with a threshold value that is determined in advance for vacant frequency determination. Determination means for outputting a determination result of the signal strength indicating whether or not the frequency is empty,
An arithmetic means for performing an operation for determining whether or not the signal strength of the own radio communication station apparatus and other radio communication station apparatus is an empty frequency around the own radio communication station apparatus;
Comprising at least
The weight correction value set in advance in the weight correction means is
Distance between wireless communication station devices, degree of correlation of received signal strength between wireless communication station devices, installation location of wireless communication station device, communication time zone of wireless communication station device, interference in past communication of wireless communication station device A wireless communication station apparatus, characterized by being determined according to any one or a plurality of occurrence history information . The radio communication station apparatus according to any one of claims 4 to 6 ,
As weight correction by the weight correction value in the weight correction means,
The measurement result of the signal strength of the own radio communication station device and the measurement result of the signal strength of the other radio communication station device transmitted from the other radio communication station device, or the terminal measurement result of the signal strength of the own radio communication station device And the terminal measurement result of the signal strength of the other radio communication station apparatus, or the addition average value of the own radio communication station apparatus and the addition average value of the other radio communication station apparatus,
It is characterized by either multiplying a weighting factor determined according to the distance between the radio communication station devices or adding or subtracting the propagation loss amount determined according to the distance between the radio communication station devices. A wireless communication station device. The radio communication station apparatus according to claim 7 ,
Regarding other wireless communication station devices existing within a predetermined distance threshold range determined in advance from the own wireless communication station device, as weight correction by the weight correction value in the weight correction means,
The measurement result of the signal strength of the other radio communication station device transmitted from the other radio communication station device, the terminal measurement result of the signal strength of the other radio communication station device, or the other radio communication station device For any of the above average values,
A radio communication station apparatus that performs either multiplication by a weighting factor of 0 or addition of a predetermined amount of propagation loss. The radio communication station apparatus according to claim 7 ,
Regarding other wireless communication station devices existing within a predetermined distance threshold range determined in advance from the own wireless communication station device, as weight correction by the weight correction value in the weight correction means,
The measurement result of the signal strength of the other radio communication station device transmitted from the other radio communication station device, the terminal measurement result of the signal strength of the other radio communication station device, or the other radio communication station device For any of the above average values,
Multiply by a weighting factor proportional to the distance between the own radio communication station apparatus and the other radio communication station apparatus, or a value inversely proportional to the distance between the own radio communication station apparatus and the other radio communication station apparatus A radio communication station apparatus characterized by subtracting the amount of propagation loss. The radio communication station apparatus according to claim 7 ,
Regarding other wireless communication station devices that exist within a range that exceeds a predetermined distance threshold predetermined from the own wireless communication station device, as weight correction by the weight correction value in the weight correction means,
The measurement result of the signal strength of the other radio communication station device transmitted from the other radio communication station device, the terminal measurement result of the signal strength of the other radio communication station device, or the other radio communication station device For any of the above average values,
Multiply a weighting factor inversely proportional to the distance between the own radio communication station apparatus and the other radio communication station apparatus, or a value proportional to the distance between the own radio communication station apparatus and the other radio communication station apparatus A radio communication station apparatus characterized by adding either of the propagation loss amounts of. The radio communication station apparatus according to any one of claims 4 to 10 ,
The calculation means outputs the determination result output from the determination means .
All of the signal strength measurement results of the own radio communication station device and other radio communication station devices, or all of the signal strength terminal measurement results of the own radio communication station device and other radio communication station devices, or the own radio communication A radio communication station apparatus that performs a calculation to detect a frequency band in which all of the addition average values of the station apparatus and the other radio communication station apparatus are determined to have a low signal intensity equal to or lower than the threshold as a vacant frequency. The wireless communication station apparatus according to any one of claims 4 to 11 ,
Used to determine the frequency band of the radio signal to be used for communication with the radio terminal device by determining whether or not the radio signal does not exist in the vicinity of the own radio communication station device. A wireless communication station apparatus, including a communication method and / or a transmission power amount to be determined. In a radio communication method in a radio communication system comprising a plurality of radio communication station apparatuses that communicate with one or more radio terminal apparatuses existing in a service area using radio signals in a frequency band assigned at the start of communication,
The wireless communication station device
While transmitting the measurement results of the measured signal strength the signal strength of the radio signals existing around the radio communication station, the another wireless communication station for all frequency bands of the utilization object,
Measurement of the signal strength that has been transmitted from another wireless communication station to receive a measurement result of the signal strength in the measurement results and other wireless communication station of the signal strength of the radio communication station based on the results, in the vicinity of the radio communication station to determine whether or not an unoccupied frequency wireless signal is not present, the determination result of determining a vacant frequency, used for communication with the wireless terminal device A wireless communication method for determining a frequency band of a wireless signal ,
When the radio communication station apparatus determines a frequency band of a radio signal used for communication with the radio terminal apparatus,
The measurement result of the signal strength measured by the own radio communication station device and the measurement result of the signal strength of the other radio communication station device transmitted from the other radio communication station device, for all frequency bands to be used, for each frequency band Is subjected to weight correction by a preset weight correction value,
The threshold value determined in advance for determining the free frequency, the signal strength measurement result of the own radio communication station device and the signal strength measurement result of the other radio communication station device transmitted from the other radio communication station device corrected for weight. Compared with, output the signal strength judgment result indicating whether it is an empty frequency,
By performing an operation for determining whether or not the signal strength determination result of the output own radio communication station apparatus and other radio communication station apparatus is an empty frequency around the own radio communication station apparatus, the radio Determine the frequency band of the radio signal used for communication with the terminal device, and
The weight correction value set in advance is
Distance between wireless communication station devices, degree of correlation of received signal strength between wireless communication station devices, installation location of wireless communication station device, communication time zone of wireless communication station device, interference in past communication of wireless communication station device A wireless communication method characterized by being determined according to any one or more of occurrence history information .   In a radio communication method in a radio communication system comprising a plurality of radio communication station apparatuses that communicate with one or more radio terminal apparatuses existing in a service area using radio signals in a frequency band assigned at the start of communication,
  The wireless terminal device
  The signal strength of a radio signal existing around the wireless terminal device for all frequency bands to be used is measured as a signal strength terminal measurement result, and is transmitted to the wireless communication station device in the service area where the wireless terminal device exists. ,
  The wireless communication station device
  While transmitting the terminal measurement result of the signal strength transmitted from one or more of the wireless terminal devices existing in the service area of the wireless communication station device to other wireless communication station devices,
  The terminal measurement result of the signal strength transmitted from another wireless communication station device is received, the terminal measurement result of the signal strength of the own wireless communication station device and the terminal measurement of the signal strength in the other wireless communication station device Based on the result, it is determined whether or not there is a free frequency in the vicinity of the own wireless communication station device and a wireless signal does not exist. Based on the determination result determined as a free frequency, it is used for communication with the wireless terminal device. A wireless communication method for determining a frequency band of a wireless signal,
  When the radio communication station apparatus determines a frequency band of a radio signal used for communication with the radio terminal apparatus,
  The terminal measurement result of the signal strength of the own wireless communication station device transmitted from one or more of the wireless terminal devices existing in the service area of the own wireless communication station device and the other wireless communication station transmitted from the other wireless communication station device The terminal measurement result of the signal strength of the device is subjected to weight correction with a weight correction value set in advance for each frequency band for all frequency bands to be used,
  The terminal measurement result of the signal strength of the own radio communication station apparatus and the terminal measurement result of the signal intensity of the other radio communication station apparatus transmitted from the other radio communication station apparatus, which have been weight-corrected, are determined in advance for use in determining a free frequency. Output a signal strength determination result indicating whether it is an empty frequency or not,
  By performing an operation for determining whether or not the signal strength determination result of the output own radio communication station apparatus and other radio communication station apparatus is an empty frequency around the own radio communication station apparatus, the radio Determine the frequency band of the radio signal used for communication with the terminal device, and
  The weight correction value set in advance is
  Distance between wireless communication station devices, degree of correlation of received signal strength between wireless communication station devices, installation location of wireless communication station device, communication time zone of wireless communication station device, interference in past communication of wireless communication station device Determined according to one or more occurrence history information
A wireless communication method.   In a radio communication method in a radio communication system comprising a plurality of radio communication station apparatuses that communicate with one or more radio terminal apparatuses existing in a service area using radio signals in a frequency band assigned at the start of communication,
  The wireless terminal device
  The signal strength of a radio signal existing around the wireless terminal device for all frequency bands to be used is measured as a signal strength terminal measurement result, and is transmitted to the wireless communication station device in the service area where the wireless terminal device exists. ,
  The wireless communication station device
  Average the terminal measurement results of the signal strength transmitted from one or a plurality of the wireless terminal devices existing in the service area of the wireless communication station device for each frequency band for all frequency bands to be used. By calculating the addition average value corresponding to the measurement result of the signal strength in its own radio communication station apparatus, while transmitting the calculated addition average value to other radio communication station apparatus,
  The addition average value transmitted from the other radio communication station apparatus is received, and the result of further averaging the addition average values of the own radio communication station apparatus and the other radio communication station apparatus is preliminarily used as a free frequency determination. Compared with the determined threshold value, it is determined whether or not there is a radio frequency in which no radio signal exists in the vicinity of the own radio communication station apparatus, and communication with the radio terminal apparatus is performed based on the determination result determined as an empty frequency. A wireless communication method for determining a frequency band of a wireless signal to be used,
  When the radio communication station apparatus determines a frequency band of a radio signal used for communication with the radio terminal apparatus,
  For the total frequency band to be used, the addition average value of the own radio communication station apparatus calculated in the own radio communication station apparatus and the addition average value of the other radio communication station apparatus transmitted from the other radio communication station apparatus are frequency bands. Each time, weight correction is performed with a preset weight correction value,
  The result obtained by further adding the addition average value of the own radio communication station apparatus and the addition average value of the other radio communication station apparatus, corrected for weight, is compared with a threshold value determined in advance for determining an empty frequency. Output a signal strength judgment result indicating whether or not
  By performing an operation for determining whether or not the signal strength determination result of the output own radio communication station apparatus and other radio communication station apparatus is an empty frequency around the own radio communication station apparatus, the radio Determine the frequency band of the radio signal used for communication with the terminal device, and
  The weight correction value set in advance is
  Distance between wireless communication station devices, degree of correlation of received signal strength between wireless communication station devices, installation location of wireless communication station device, communication time zone of wireless communication station device, interference in past communication of wireless communication station device Determined according to one or more occurrence history information
A wireless communication method.

Images