JP2009267815A - Interference amount estimating method, radio communication method, radio communication system, and radio communication apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a radio communication system in which each radio communication system effectively disposes many terminals within the system even when a plurality of radio communication systems exist together within the same area. <P>SOLUTION: In the plurality of radio communication systems, a first radio communication apparatus of one radio communication system obtains a frequency and RF parameter information to be used by a second radio communication apparatus belonging to the other radio communication system. The first radio communication apparatus measures reception power of a radio signal of a frequency to be used by the second radio communication apparatus, then calculates an interference amount which is given to the second radio communication apparatus based on the reception power, the RF parameter information of the second radio communication apparatus, and the RF parameter information stored in a self apparatus. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an interference amount estimation method for estimating an interference amount that a first wireless communication device of one wireless communication system gives to a second wireless communication device of the other wireless communication system in a plurality of wireless communication systems, and wireless communication The present invention relates to a method, a wireless communication system, and a wireless communication apparatus.

  In recent years, with the spread of mobile phones, wireless local area networks (LANs), and the like, a communication system technology that can accommodate a large number of terminal devices in a base station device using a limited frequency band is required. For example, a cognitive (hereinafter, referred to as cognitive) radio technology has attracted attention as a means for effectively using frequencies. The cognitive radio technology is a technology in which a wireless device recognizes a surrounding radio wave environment, selects an appropriate frequency band, etc., and performs wireless communication, thereby effectively utilizing an available frequency band. The cognitive radio can effectively use frequencies and time that have not been attracting attention in the past, so that the frequency band used per unit area can be greatly improved. Non-patent document 1 discloses the cognitive radio technology.

  Here, when two systems share the time using signals in the same frequency band as in cognitive radio technology, one system is not affected by interference from the other system, or It is necessary to detect the interference signal so as not to interfere with the other party's system. As a technique for detecting the arrival of an interference signal with high accuracy, a method of estimating an interference signal from received power is known.

However, in this method, when the CNR (Carrier to Noise ratio) is low, an error of the interference signal occurs. As a technique for improving this, a method of detecting an interference signal using a cyclostationary signal has been proposed. This is disclosed in Non-Patent Document 2, for example. In this detection method, signal detection is possible even in the case of a very low CNR if the carrier frequency of one radio communication system (for example, the primary system) in the cognitive system or the symbol rate and the modulation method are known in advance. It becomes possible.
S. Haykin, “Cognitive radio: brain-empowered wireless Communications, IEEE Journal on J-SAC, no.2, vol.23, pp.201-220, Feb.2005” D.cabric, SMMishra, and RWBrodersen, “Implementationissues in spectrum sensing for cognitive radios”, Conference Record of the Thirty-Eighth Asilomar Conference, vol.1, pp.772-776, 7-10 / Nov / 2004.

  However, the interference signal detection method disclosed in Patent Document 2 requires a very large amount of time and the number of signal samples to detect the interference signal. Since a problem such as difficulty arises, there is a problem that many terminals cannot be arranged in the system.

  Therefore, the present invention provides a wireless communication method, a wireless communication system, and a wireless communication in which each wireless communication system can efficiently arrange many terminals in the system when a plurality of wireless communication systems coexist in the same area. An object of the present invention is to provide an apparatus and an interference amount estimation method.

  To achieve the above object, the present invention estimates, in a plurality of wireless communication systems, the amount of interference that a first wireless communication device of one wireless communication system gives to a second wireless communication device of the other wireless communication system. In the interference amount estimation method, the second wireless communication apparatus information acquisition unit of the first wireless communication apparatus acquires the frequency and RF parameter information used by the second wireless communication apparatus, and the first wireless communication apparatus The received power measuring means measures the received power of the radio signal of the frequency used by the second wireless communication apparatus, and the interference amount calculating means of the first wireless communication apparatus is configured to receive the received power and the second wireless communication apparatus. The amount of interference given to the second wireless communication device is calculated based on the RF parameter information of the device and the stored RF parameter information of the device itself.

  According to the present invention, in the above-described interference amount estimation method, the RF parameter information is at least a transmission amplifier gain and a reception amplifier gain, and the interference amount calculation means of the first wireless communication apparatus is configured to transmit the second wireless communication device. An interference signal noise power ratio is derived from the received power obtained from the radio signal transmitted from the apparatus to the own apparatus, the interference signal noise power ratio, and the reception amplifier of the second radio communication apparatus and the first radio communication apparatus Calculating an amount of interference given to the second wireless communication device by the own device based on a difference in gain and a difference in the transmission amplifier gain between the second wireless communication device and the first wireless communication device; To do.

  According to the present invention, in the plurality of wireless communication systems, each of the first wireless communication apparatus of one wireless communication system and the second wireless communication apparatus of the other wireless communication system is assigned to each wireless communication system. A radio communication method in which radio communication devices belonging to a radio communication system perform radio communication with each other in each radio communication system using a frequency band and a common frequency band assigned to each radio communication system in common. The second wireless communication device information acquisition means of the first wireless communication device acquires the dedicated frequency band and RF parameter information used by the second wireless communication device, and the received power measurement means of the first wireless communication device Measures the received power in the dedicated frequency band used by the second wireless communication device, and the interference amount calculation means of the first wireless communication device Based on the received power, the RF parameter information of the second wireless communication device, and the stored RF parameter information of the own device, the amount of interference given to the second wireless communication device is calculated, and the first wireless communication device An interference amount comparison unit compares the calculated interference amount with a predetermined interference amount threshold value, and an allocated frequency determination unit of the first wireless communication apparatus determines whether the first wireless communication apparatus belongs to all the second wireless communication systems. 2 When the amount of interference given to the wireless communication device is larger than the threshold value, it is determined that the common frequency band can be assigned to the own device, and all the second wireless communication devices belonging to the other wireless communication system When the amount of interference given to the wireless communication system is equal to or less than the threshold, it is determined that the dedicated frequency band of the wireless communication system to which the device belongs can be allocated. .

  According to the present invention, in the above wireless communication method, the RF parameter information is at least a transmission amplifier gain and a reception amplifier gain, and the interference amount calculation means of the first wireless communication device is the second wireless communication device. The interference signal noise power ratio is derived from the received power obtained from the radio signal transmitted from the radio apparatus to the own apparatus, the interference signal noise power ratio, and the reception amplifier gain of the second radio communication apparatus and the first radio communication apparatus And the amount of interference given to the second wireless communication device by the own device based on the difference between the second wireless communication device and the difference between the transmission amplifier gains of the second wireless communication device and the first wireless communication device. .

  According to the present invention, in the plurality of wireless communication systems, each of the first wireless communication apparatus of one wireless communication system and the second wireless communication apparatus of the other wireless communication system is assigned to each wireless communication system. A radio communication system in which radio communication apparatuses belonging to a radio communication system perform radio communication with each other in each radio communication system using a frequency band and a common frequency band assigned to each radio communication system in common. The first wireless communication device acquires a dedicated frequency band and RF parameter information used by the second wireless communication device, and a dedicated frequency used by the second wireless communication device. Received power measuring means for measuring received power in a band, the received power, and RF parameter information of the second wireless communication device; Based on the stored RF parameter information of the own device, the interference amount calculating means for calculating the amount of interference given to the second wireless communication device is compared with the calculated interference amount and a predetermined threshold of interference amount. If the interference amount given to the interference amount comparison means and all the second wireless communication devices belonging to the other wireless communication system is larger than the threshold, it is determined that the common frequency band can be allocated to the own device. When the amount of interference given to all the second radio communication devices belonging to the other radio communication system is equal to or less than the threshold, the dedicated frequency band of the radio communication system to which the own device belongs can be allocated. An assigned frequency determining means for determining comprises a wireless communication system.

  According to the present invention, in the above wireless communication system, the RF parameter information is at least a transmission amplifier gain and a reception amplifier gain, and the interference amount calculation means of the first wireless communication device is the second wireless communication device. The interference signal noise power ratio is derived from the received power obtained from the radio signal transmitted from the radio apparatus to the own apparatus, the interference signal noise power ratio, and the reception amplifier gain of the second radio communication apparatus and the first radio communication apparatus And the amount of interference given to the second wireless communication device by the own device based on the difference between the second wireless communication device and the difference between the transmission amplifier gains of the second wireless communication device and the first wireless communication device. .

  According to the present invention, in the plurality of wireless communication systems, each of the first wireless communication apparatus of one wireless communication system and the second wireless communication apparatus of the other wireless communication system is assigned to each wireless communication system. In a radio communication system in which radio communication devices belonging to the radio communication system perform radio communication with each other in each radio communication system using a frequency band and a common frequency band assigned to each radio communication system in common. A second wireless communication device information acquisition means for acquiring dedicated frequency band and RF parameter information used by the second wireless communication device, and a dedicated frequency used by the second wireless communication device; Received power measuring means for measuring received power in a band, the received power, and an RF parameter of the second wireless communication device Based on the information and the stored RF parameter information of the device, interference amount calculating means for calculating the amount of interference given to the second wireless communication device, the calculated interference amount and a predetermined interference amount threshold value, If the amount of interference given to all the second wireless communication devices belonging to the other wireless communication system is larger than the threshold, the common frequency band is assigned to the own device. If the amount of interference given to all the second radio communication devices belonging to the other radio communication system is equal to or less than the threshold, the dedicated frequency band of the radio communication system to which the device belongs belongs. And an allocated frequency determining means for determining that it is possible.

  According to the present invention, when a plurality of wireless communication systems overlap in the same area and each wireless communication system can perform wireless communication using different frequency bands and a common frequency band, When the terminal is in a position that does not affect the interference of the radio signal with respect to the terminal belonging to the other radio communication system, the terminal uses the radio communication in the common frequency band. As a result, the frequency band dedicated to the wireless communication system can be freed, so that other terminals can be accommodated, and this mechanism can increase the number of terminals connected to the wireless communication system. That is, when a number of wireless communication systems coexist in the same area, each wireless communication system can efficiently arrange many terminals in the system.

Hereinafter, a wireless communication system according to an embodiment of the present invention will be described with reference to the drawings.
FIG. 1 is a first diagram showing a system configuration of a wireless communication system according to the embodiment.
In the wireless communication system in this figure, an example is shown in which two wireless communication systems, a wireless communication system A and a wireless communication system B, coexist in the same area. First, it is assumed that the wireless communication system A includes an access point device (AP) 10, and four terminals 1a, 2a, 3a, and 4a are wirelessly connected to the AP 10. In addition, the AP 10 and the terminals 1a, 2a, 3a, and 4a are normally connected for communication using a frequency band dedicated to the wireless communication system A used only by the wireless communication system A. In FIG. 1, in the initial stage, the radio communication system A uses a frequency of # a1 and a terminal 2a uses a frequency of # a2 in a frequency band dedicated to the radio communication system A. Assume that 3a uses the frequency of # a3 and the terminal 4a uses the frequency of # 4a to transmit and receive signals to and from the AP 10.

  The wireless communication system B includes an access point device (AP) 20, and three terminals 1b, 2b, and 3b are wirelessly connected to the AP 20. In addition, the AP 20 and the terminals 1b, 2b, and 3b are normally connected for communication using a frequency band dedicated to the wireless communication system B used only by the wireless communication system B. In FIG. 1, in an initial stage, the radio communication system B uses a frequency of # b1, a terminal 2b uses a frequency of # b2 in a frequency band dedicated to the radio communication system B, and a terminal Assume that 3b uses the frequency of # b3 to transmit / receive a signal to / from the AP 20.

  In the wireless communication system A and the wireless communication system B, several terminals in each communication system can communicate using a common frequency band common to both wireless communication systems. That is, in the radio communication system A, the AP 10 and the terminals 1a to 4a can be connected to each other using the common use frequency band in addition to the frequency band dedicated to the radio communication system A. Further, the radio communication system B can also connect the AP 20 and the terminals 1b to 3b using a common use frequency band in addition to the frequency band dedicated to the radio communication system B. Here, when a terminal in the wireless communication system A communicates with the AP 10 using the common use frequency band, or when a terminal in the wireless communication system B communicates with the AP 20 using the common use frequency band, It is necessary that the terminal in one radio communication system is in a position that does not affect the other radio communication system. A terminal in one radio communication system communicates with an AP (access point apparatus) using the common frequency band only when it is found that the terminal is in a position that does not affect the other radio communication system. You will be able to connect.

FIG. 2 is a functional block diagram of the access point device and the terminal.
As shown in this figure, APs (access point devices) 10 and 20 include an antenna 100, a TDD (Time Division Duplex) switch 101, a receiving unit 102 that receives and processes a signal, a transmitting unit 103 that transmits a signal, and a received signal. Received signal branching section 104, subcarrier information acquiring section 105 for acquiring subcarrier information of another system, received power determining section 106 for signals received by other systems, and interference estimation for estimating signal interference to be given to other systems Unit 107, subcarrier candidate information acquisition unit 108 that acquires subcarrier candidate information for the own system, channel determination unit 109 that determines a channel (frequency) used for communication with the terminal, and a transmission signal generation unit that generates a transmission signal 110.

  2, the terminals 1a to 4a and 1b to 3b include an antenna 200, a TDD (Time Division Duplex) switch 201, a reception unit 202 that receives and processes a signal, a transmission unit 203 that performs transmission processing of a signal, and a reception signal. Received signal branching section 204, subcarrier information acquiring section 205 for acquiring subcarrier information of other systems, received power judgment section 206 for signals received by other systems, and interference estimation for estimating signal interference given to other systems 207, a channel determination unit 208 that determines a channel (frequency) used for communication with the access point device (AP), and a transmission signal generation unit 209 that generates a transmission signal.

Next, processing in the wireless communication system will be described.
In the wireless communication system A and the wireless communication system B, each terminal communicating with the access point device (AP10 or AP20) communicates with the access point device (AP10 or AP20) belonging to the wireless communication system to which the terminal belongs. The frequency used for communication and the order of transmission / reception times must be determined with other terminals in the wireless communication system. The determination of the frequency used for communication and the order of transmission and reception times is hereinafter referred to as scheduling. Since scheduling information (frequency information to be used in this embodiment) is used by each AP and terminal, the AP and terminal always exchange this scheduling information by exchanging with each other. .

  FIG. 1 shows an example in which OFDMA (Orthogonal Frequency Division Multiplexing Access) is used when a terminal channel is divided by frequency. As described above, in the initial state, in the wireless communication system A, the AP 10 and the terminals 1a to 4a transmit and receive scheduling information, and the terminal 1a has the frequency # a1 in the frequency band dedicated to the wireless communication system A. , Terminal 2a uses # a2 frequency, terminal 3a uses # a3 frequency, and terminal 4a uses # 4a frequency to transmit and receive signals to and from AP10. In the initial state, in the wireless communication system B, the A20 and the terminals 1b to 4b transmit and receive scheduling information, and the terminal 1b uses the frequency # b1 in the dedicated frequency band for the wireless communication system B. Assume that 2b uses the frequency of # b2, and the terminal 3b uses the frequency of # b3 to transmit and receive signals to and from the AP 20.

  Here, in order to determine that the dedicated frequency bands normally used in the radio communication system A and the radio communication system B do not interfere with each other using the scheduling information, the radio communication system A and the radio communication system B In addition to the scheduling information transmitted and received within the local system, scheduling information transmitted and received in the other wireless communication system is received, and based on the scheduling information, dedicated frequency bands that are normally used interfere with each other. It will be determined whether or not.

FIG. 3 is a second diagram showing a system configuration of the wireless communication system according to the embodiment.
First, the channel allocation for each terminal in the wireless communication system A in the state of FIG. 1 is determined. At this time, the AP 10 and the terminals 1a to 4a of the wireless communication system A, from the signals transmitted and received by the AP 20 and the terminals 1b to 3b of the wireless communication system B, the antenna parameters (amplifier and antenna gain) of the wireless communication system B, Scheduling information is detected, and each frequency (channel) used by the AP 20 and the terminals 1b to 3b in the wireless communication system B can be detected based on the information. Based on the detected frequency, it is estimated whether the radio communication system A is causing signal interference to the radio communication system B and whether the radio communication system B is likely to cause signal interference to the radio communication system A. be able to.

  As shown in FIG. 3, if the three terminals 1 a to 3 a of the wireless communication system A are far from the wireless communication system B, the three terminals 1 a to 3 a share the same terminal as the wireless communication system B. Even if the common frequency to be used is assigned, there is no problem of signal interference with the radio communication system B. Therefore, any frequency in the common use frequency band can be allocated to the terminals 1a to 3a of the wireless communication system A at the time of channel allocation. On the other hand, since the terminal 4a of the wireless communication system A is located in the vicinity of the communication area of the wireless communication system B, if a common use frequency band is assigned to this terminal 4a, the AP 20, the terminal 2b, and the terminal 3b of the wireless communication system B are allocated. May cause signal interference due to interference waves. Therefore, it can be determined that it is desirable to allocate the dedicated frequency band of the wireless communication system A to the terminal 4a of the wireless communication system A in order to avoid signal interference.

FIG. 4 is a third diagram showing a system configuration of the wireless communication system according to the embodiment.
After the determination result of channel assignment in the wireless communication system A shown in FIG. Also in the wireless communication system B, the AP 20 and the terminals 1b to 4b receive the antenna parameters (amplifier and antenna gain) and scheduling of the wireless communication system A from the signals transmitted and received by the AP 10 and the terminals 1a to 4a of the wireless communication system A. Information is detected, and each frequency (channel) used by the AP 10 and the terminals 1a to 4a in the wireless communication system A can be detected based on the information. Based on the detected frequency, it is estimated whether the radio communication system B is causing signal interference to the radio communication system A and whether the radio communication system A is likely to cause signal interference to the radio communication system B. be able to.

  As shown in FIG. 4, if the terminal 1b of the wireless communication system B is far away from the wireless communication system A, even if a common frequency used in common with the wireless communication system A is assigned to the terminal 1b, There is no problem of signal interference for the wireless communication system A. Accordingly, any frequency in the common use frequency band can be allocated to the terminal 1b of the radio communication system B at the time of channel allocation. On the other hand, since the terminals 2b and 3b of the wireless communication system B are located in the vicinity of the communication area of the wireless communication system A, if a common use frequency band is allocated to the terminals 2b and 3b, the AP 10 of the wireless communication system A and each There is a possibility of causing signal interference due to interference waves to any of the terminals. Therefore, it can be determined that it is desirable to allocate the dedicated frequency band of the radio communication system B to the terminals 2b and 3b of the radio communication system B in order to avoid signal interference.

  3 and FIG. 4, in the wireless communication system A, the frequencies # a1 to # a3 are vacant, and the frequencies can be assigned to another new terminal. In the wireless communication system B, since the frequency of # b1 is vacant, the frequency can be assigned to another new terminal. That is, the number of terminals accommodated in the wireless communication system A and the wireless communication system B can be increased.

Hereinafter, a method for estimating interference power will be described. In the following description, the interference that the AP 10 of the wireless communication system A receives from the AP 20 of the wireless communication apparatus B will be described as an example.
First, the received power R _{(AP20−AP10) at the AP 10} and the interference signal noise power cost (INR _AP10 ) of the _AP 10 can be expressed by the following equations (1) and (2).

In these equations (1) and (2), G represents the gain of the amplifier and the antenna. Further, the suffix HPA indicates a transmission amplifier, LNA indicates a reception amplifier, and ANT indicates an antenna. Subscripts AP20 and AP10 indicate information generated in AP20 or AP10. L represents a path loss of the propagation path. Similarly, the received power R _(AP10-AP20) of the interference signal from AP10 to AP20 at AP20 and the interference signal noise power cost ( _INRAP20 ) of _AP20 are expressed by the following equations (3) and (3). Can do.

  Here, when the operation of {Expression (3) −Expression (1)} is performed, the following relational expression (5) is obtained.

In addition, since the reversibility of the propagation path is established, the relationship L _{(AP20−AP10)} = L _{(AP10−AP20)} is established. Then, using Expressions (2), (4), and (5), Expression (6) is obtained.

  That is, the interference from AP 10 to AP 20 can be given by equation (6). This is expressed by INR obtained by transmitting from AP20 to AP10, a difference between gains of AP20 and AP10, and a difference between gains of AP10 and AP20. The first term of Equation (6) is obtained when the AP 10 receives a received signal, and the second and third terms can be realized by knowing the gain of the amplifier of another wireless communication system. Similarly, this estimation can be performed between the AP and the terminal and between the terminal and the terminal between the wireless communication system A and the wireless communication system B.

FIG. 5 is a diagram showing a process flow of the use frequency determination process.
Next, the processing flow in this embodiment will be described.
First, in each of the wireless communication system A and the wireless communication system B, a frequency to be used is determined (step S101). For example, since the AP 10 of the wireless communication system A assigns each frequency of the dedicated frequency band stored in advance to each of the terminals 1a to 5a, scheduling information holding information on different frequencies within the dedicated frequency band is assigned to each of the terminals 1a to 5a. It may be transmitted to the terminals 1a to 5a, or triggered by receiving a signal from any one of the terminals 1a to 5a, the AP 10 stores scheduling information holding information on frequencies that are not available to the terminal. You may make it transmit. The same applies to the wireless communication system B.

  The terminals 1a to 5a receive the control channel transmitted from either the AP 20 of the wireless communication system B or the terminals 1b to 3b (reception processing is performed by the receiving unit 202 of the terminal), and the control channel The included scheduling information is detected (step S102). Thereby, the scheduling information is analyzed, and the frequency used in the radio communication system B is detected (frequency detection processing is performed by the subcarrier information acquisition unit 205 of the terminal; step S103). That is, each of the terminals 1a to 5a of the wireless communication system A has a function of receiving a frequency band of a signal transmitted from the AP 20 or the terminals 1b to 3b of the wireless communication system B.

  Similarly, the terminals 1b to 3b of the wireless communication system B have a function of receiving the frequency band of signals transmitted from the AP 10 of the wireless communication system A and the terminals 1a to 5a, and the AP 10 of the wireless communication system A. Alternatively, the control channel transmitted from any of the terminals 1a to 5a is received, and the scheduling information included in the control channel is received, whereby the scheduling information is analyzed and used in the radio communication system A. Detect frequency. The number k of scheduling information in the control channel received by the wireless communication system A is determined by “number of users × number of frequencies used by each user” of the wireless communication system B. Hereinafter, since the processes of the terminals 1a to 5a in the wireless communication system A and the processes of the terminals 1b to 3b in the wireless communication system B are the same, only the terminal 1a process of the wireless communication system A will be described.

Next, the received power determination unit 206 of the terminal 1a of the wireless communication system A uses the received power when the control channel including the _Nth scheduling information _{kN (N = 1} to _k) of the scheduling information k is received. It detects (step S104). Then, the interference estimation unit 207 of the terminal 1a calculates an interference amount α given to the wireless communication system B (step S105). This calculation method can be obtained by the relationship of the above-described equations (1) to (6). Here, a threshold value of the interference amount is stored in advance in a memory or the like, and the interference estimation unit 207 of the terminal 1a determines whether or not the calculated interference amount α is equal to or less than the threshold value stored in the memory or the like. Determination is made (step S106). If the amount of interference α is equal to or less than the threshold, it is determined that no interference is given to the control channel signal including the scheduling information k _N received from the wireless communication system B. The terminal 1a determines whether or performs processing for all signal of the control channel corresponding to all of the scheduling information k _N of 1 to k (step S107), when performing processing of all, all of the interfering It is determined whether the amount α is equal to or less than a threshold (step S108). Then, it is determined that not more than the amount of interference all given the signal of the control channel corresponding to all of the scheduling information k _N of 1 to k, can utilize a common frequency used (step S109).

  When the interference estimation unit 207 of the terminal 1a determines that the common use frequency can be used, the channel determination unit 208 is notified of the use of the common use frequency, and the channel determination unit 208 uses the common use frequency. The request information is transmitted to the AP 10 (step S110). When the AP 10 receives the common use frequency use request from the terminal 1a, the AP 10 determines whether the common use frequency is available. If there is, the AP 10 is available to the terminal 1a that has transmitted the common use frequency use request. The scheduling information storing the information on the common frequency used is transmitted and received by the terminal 1a (step S111). Information on whether or not there is a vacancy in the common use frequency may be stored in a memory or the like. Thereby, when the information of the common use frequency is stored in the scheduling information addressed to the own terminal from the AP 10, the channel determination unit 208 of the terminal 1 a performs wireless communication with the AP 10 using the common use frequency. This is performed (step S112). In step S108, if all the interference amounts α for the terminals of the wireless communication system B and the AP 20 are not less than or equal to the threshold value, it is determined that the dedicated frequency band determined in step S101 is used as it is.

  And the process similar to the above-mentioned terminal 1a is performed by the terminals 2a to 5a of the wireless communication system A and the terminals 1b to 3b belonging to the wireless communication system B. By the processing of each terminal, as shown in FIG. 4, the terminals 1 a to 3 a and the terminal 1 b transmit and receive information to and from the AP in the wireless communication system to which the terminal 1 a to 3 a and the terminal 1 b belong. In addition, it is necessary to share information on which one of a plurality of assigned frequencies in the common use frequency band has already been assigned by exchanging information between the AP 10 and the AP 20. Also in the wireless communication system B, the same processing as that of the wireless communication system A is performed, and any one of the terminals 1b to 3b that have been determined not to interfere with the wireless communication system A is a common frequency. You may make it communicate with AP20 using.

  As described above, the embodiments of the present invention have been described. According to the above-described processing, a plurality of wireless communication systems are overlapped in the same area, and each wireless communication system uses different frequency bands and a common frequency band for wireless communication. When possible, if a terminal in one radio communication system is in a position that does not affect the radio signal interference to a terminal belonging to the other radio communication system, It uses wireless communication in the frequency band. As a result, the frequency band dedicated to the wireless communication system can be freed, so that other terminals can be accommodated, and this mechanism can increase the number of terminals connected to the wireless communication system. That is, when a number of wireless communication systems coexist in the same area, each wireless communication system can efficiently arrange many terminals in the system.

  The above-described AP and terminal have a computer system inside. Each process described above is stored in a computer-readable recording medium in the form of a program, and the above process is performed by the computer reading and executing the program. Here, the computer-readable recording medium means a magnetic disk, a magneto-optical disk, a CD-ROM, a DVD-ROM, a semiconductor memory, or the like. Alternatively, the computer program may be distributed to the computer via a communication line, and the computer that has received the distribution may execute the program.

  The program may be for realizing a part of the functions described above. Furthermore, what can implement | achieve the function mentioned above in combination with the program already recorded on the computer system, and what is called a difference file (difference program) may be sufficient.

It is a 1st figure which shows the system configuration | structure of a radio | wireless communications system. It is a functional block diagram of an access point apparatus and a terminal. It is a 2nd figure which shows the system configuration | structure of a radio | wireless communications system. It is a 3rd figure which shows the system configuration | structure of a radio | wireless communications system. It is a figure which shows the processing flow of a use frequency determination process.

Explanation of symbols

1a to 5a, 1b to 5b ... terminal 10, 20 ... access point device (AP)
101, 201 ... TDD switch 102, 202 ... receiving section 103, 203 ... transmitting section 104, 204 ... received signal branching section 105, 205 ... subcarrier information acquiring section 106, 206 ... Received power judgment unit 107, 207 ... Interference estimation unit 108 ... Subcarrier candidate information acquisition unit 109, 208 ... Channel determination unit 110, 209 ... Transmission signal generation unit

Claims (7)

In a plurality of wireless communication systems, an interference amount estimation method for estimating an interference amount that a first wireless communication device of one wireless communication system gives to a second wireless communication device of the other wireless communication system,
The second wireless communication device information acquisition means of the first wireless communication device acquires the frequency and RF parameter information used by the second wireless communication device;
The received power measuring means of the first wireless communication device measures the received power of a radio signal of a frequency used by the second wireless communication device;
Based on the received power, the RF parameter information of the second wireless communication device, and the stored RF parameter information of the own device, the interference amount calculation means of the first wireless communication device transmits the interference amount to the second wireless communication device. An interference amount estimation method characterized by calculating an interference amount to be given. The RF parameter information is at least a transmission amplifier gain and a reception amplifier gain,
The interference amount calculation means of the first wireless communication apparatus derives an interference signal noise power ratio from the received power obtained from the wireless signal transmitted from the second wireless communication apparatus to the own apparatus, and the interference signal noise power ratio And the difference between the reception amplifier gains of the second wireless communication device and the first wireless communication device and the difference between the transmission amplifier gains of the second wireless communication device and the first wireless communication device. The interference amount estimation method according to claim 1, wherein an interference amount that the device gives to the second wireless communication device is calculated. In the plurality of wireless communication systems, each of the first wireless communication device of one wireless communication system and the second wireless communication device of the other wireless communication system has a dedicated frequency band assigned to each wireless communication system, and A wireless communication method in which wireless communication devices belonging to the wireless communication system perform wireless communication with each other in each wireless communication system using a common frequency band assigned to the wireless communication system in common,
The second wireless communication device information acquisition means of the first wireless communication device acquires the dedicated frequency band and RF parameter information used by the second wireless communication device;
The received power measuring means of the first wireless communication device measures the received power in a dedicated frequency band used by the second wireless communication device;
Based on the received power, the RF parameter information of the second wireless communication device, and the stored RF parameter information of the own device, the interference amount calculation means of the first wireless communication device transmits the interference amount to the second wireless communication device. Calculate the amount of interference
The interference amount comparison means of the first wireless communication device compares the calculated interference amount with a predetermined threshold of interference amount,
When the amount of interference given to all the second wireless communication devices belonging to the other wireless communication system by the allocated frequency determination means of the first wireless communication device is larger than the threshold, the common frequency is transmitted to the own device. When it is determined that band allocation is possible and the amount of interference given to all the second wireless communication devices belonging to the other wireless communication system is equal to or less than the threshold value, the dedicated wireless communication system to which the own device belongs A wireless communication method, characterized by determining that a frequency band can be allocated. The RF parameter information is at least a transmission amplifier gain and a reception amplifier gain,
The interference amount calculating means of the first wireless communication device is
An interference signal noise power ratio is derived from the received power obtained from the radio signal transmitted from the second radio communication apparatus to the own apparatus, and the interference signal noise power ratio, the second radio communication apparatus, and the first radio communication are calculated. Based on the difference between the reception amplifier gains of the devices and the difference between the transmission amplifier gains of the second wireless communication device and the first wireless communication device, the amount of interference given by the own device to the second wireless communication device is calculated. The wireless communication method according to claim 3, wherein: In the plurality of wireless communication systems, each of the first wireless communication device of one wireless communication system and the second wireless communication device of the other wireless communication system has a dedicated frequency band assigned to each wireless communication system, and A wireless communication system in which wireless communication devices belonging to the wireless communication system perform wireless communication with each other in each wireless communication system using a common frequency band assigned in common to the wireless communication system,
The first wireless communication device is
Second wireless communication device information acquisition means for acquiring dedicated frequency band and RF parameter information used by the second wireless communication device;
Received power measuring means for measuring received power in a dedicated frequency band used by the second wireless communication device;
An interference amount calculating means for calculating the amount of interference given to the second wireless communication device based on the received power, the RF parameter information of the second wireless communication device, and the RF parameter information of the own device to be stored;
An interference amount comparison means for comparing the calculated interference amount with a predetermined threshold of interference amount;
If the amount of interference given to all the second radio communication devices belonging to the other radio communication system is larger than the threshold, it is determined that the common frequency band can be allocated to the own device, and the other radio Allocation frequency determination means for determining that the dedicated frequency band of the radio communication system to which the device belongs can be allocated when the amount of interference given to all the second radio communication devices belonging to the communication system is equal to or less than the threshold value When,
A wireless communication system comprising: The RF parameter information is at least a transmission amplifier gain and a reception amplifier gain,
The interference amount calculating means of the first wireless communication device is
An interference signal noise power ratio is derived from the received power obtained from the radio signal transmitted from the second radio communication apparatus to the own apparatus, and the interference signal noise power ratio, the second radio communication apparatus, and the first radio communication are calculated. Based on the difference between the reception amplifier gains of the devices and the difference between the transmission amplifier gains of the second wireless communication device and the first wireless communication device, the amount of interference given by the own device to the second wireless communication device is calculated. The wireless communication system according to claim 5. In the plurality of wireless communication systems, each of the first wireless communication device of one wireless communication system and the second wireless communication device of the other wireless communication system has a dedicated frequency band assigned to each wireless communication system, and The first wireless communication in a wireless communication system in which wireless communication devices belonging to the wireless communication system perform wireless communication with each other in each wireless communication system using a common frequency band assigned to the wireless communication system in common. A device,
Second wireless communication device information acquisition means for acquiring dedicated frequency band and RF parameter information used by the second wireless communication device;
Received power measuring means for measuring received power in a dedicated frequency band used by the second wireless communication device;
An interference amount calculating means for calculating the amount of interference given to the second wireless communication device based on the received power, the RF parameter information of the second wireless communication device, and the RF parameter information of the own device to be stored;
An interference amount comparison means for comparing the calculated interference amount with a predetermined threshold of interference amount;
If the amount of interference given to all the second radio communication devices belonging to the other radio communication system is larger than the threshold, it is determined that the common frequency band can be allocated to the own device, and the other radio Allocation frequency determination means for determining that the dedicated frequency band of the radio communication system to which the device belongs can be allocated when the amount of interference given to all the second radio communication devices belonging to the communication system is equal to or less than the threshold value When,
A wireless communication apparatus comprising:

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