JP2010041285A - Multiband radio communication system and terminal device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a multiband radio communication system which can reduce an amount of information which a terminal device transmits to a base station device. <P>SOLUTION: In the multiband radio communication system composed of a base station device and a terminal device under the base station device and performing communication by using discontinuous frequency bands, a reception controller 20 of the terminal device selects at least one frequency band from among frequency bands available for communication, and transmits information regarding the frequency band to the base station device as a channel quality. A transmission controller 10 of the base station device performs frequency allotment control to the terminal device based on the channel quality received from the terminal device when a communication request is received from a specific terminal device. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a multiband wireless communication system that performs communication using a plurality of discontinuous frequency bands.

  In recent years, construction of a high-speed wireless communication system has been demanded due to high demand for high-speed communication. Further, with an increase in communication speed, a wireless communication system needs to use a wider frequency band, but there is a limit to a usable frequency band. In particular, it is difficult to allocate one continuous wide frequency band to one wireless communication system from the viewpoint of frequency allocation policy. Therefore, there is a demand for a technique for constructing one wireless communication system using a plurality of discontinuous frequency bands. Such a system is generally called “multiband system” or “spectrum aggregation” (hereinafter referred to as “multiband system”).

  Patent Document 1 below discloses a method in which a base station apparatus allocates frequency bands to terminal apparatuses based on propagation characteristics and QoS (Quality of Service) in each frequency band in a multiband system. Non-Patent Document 1 below discloses a method in which a base station apparatus allocates as high a frequency band as possible to a terminal apparatus based on channel quality information of a plurality of frequency bands notified from the terminal apparatus. .

JP 2006-094001 A Y.Hara, K.Oshima "Multiband mobile communication system for wide coverage and high data rate," IEICE Trans. On Commun. Vol.E89-B, no.9, pp.2537-2547, Sep.2006.

  According to the above conventional technique, in order for the base station apparatus to appropriately allocate the frequency band to the terminal apparatus, it is necessary to grasp the channel quality for each frequency band. And in order to grasp | ascertain channel quality in a base station apparatus, it is necessary for a terminal device to notify the channel quality of each frequency band to a base station apparatus. However, when the base station apparatus receives notification of channel quality from a plurality of terminal apparatuses in the communication area, the amount of information for frequency band allocation increases, and the processing load on the frequency band allocation control by the base station apparatus There was a problem that would become high.

  The present invention has been made in view of the above, and an object of the present invention is to obtain a multiband wireless communication system capable of reducing the amount of information transmitted from a terminal device to a base station device.

  In order to solve the above-described problems and achieve the object, the present invention is a multiband radio configured by a base station device and a terminal device under the base station device, and performing communication using a plurality of discontinuous frequency bands. In the communication system, the terminal apparatus selects at least one frequency band from frequency bands available for communication, and transmits information on the frequency band to the base station apparatus as channel quality, and the base station When a device receives a communication request from a specific terminal device, the device performs frequency allocation control on the terminal device based on the channel quality received from the terminal device.

  According to the present invention, there is an effect that the terminal device can reduce the amount of channel quality information transmitted to the base station device.

  Embodiments of a multiband wireless communication system according to the present invention will be described below in detail with reference to the drawings. Note that the present invention is not limited to the embodiments.

Embodiment 1 FIG.
FIG. 1 is a diagram illustrating a configuration example of a multiband wireless communication system according to the present embodiment. Specifically, a transmission control unit 10 in a base station device and a terminal device included in the multiband wireless communication system It is a figure which shows each structural example of the reception control part 20 of. Moreover, FIG. 2 is a figure which shows an example of the frequency band which can be utilized in the multiband radio | wireless communications system of this Embodiment. In this embodiment, as an example, three discontinuous frequency bands of f1, f2, and f3 are used. The magnitudes of the frequency bands f1, f2, and f3 have a relationship of f1 <f2 <f3.

  In FIG. 1, the transmission control unit 10 of the base station apparatus includes a channel quality reception unit 11, a frequency band management unit 12, a signal generation unit 13, a frequency band f1 transmission unit 14-1, and a frequency band f2 transmission unit 14. -2 and a frequency band f3 transmitter 14-3.

  The channel quality receiving unit 11 receives channel quality (to be described later) from the terminal device and transfers the channel quality to the frequency band management unit 12. The frequency band management unit 12 manages a plurality of frequency bands (f1, f2, f3) in a unified manner, and further grasps the current traffic state, the used frequency band of the terminal device, the channel quality, and the like. Also, when a communication request is received from a specific terminal device, frequency band allocation control (frequency allocation control) is performed based on the channel quality obtained from the terminal device. The signal generation unit 13 generates a control signal (including a pilot signal) and a data signal, and transfers the generated signal to a predetermined transmission unit based on frequency allocation control by the frequency band management unit 12. The frequency band f1 transmission part 14-1 transmits a control signal or a data signal to a terminal device using the frequency band f1. The frequency band f2 transmission unit 14-2 transmits a control signal or a data signal to the terminal device using the frequency band f2. The frequency band f3 transmission unit 14-3 transmits a control signal or a data signal to the terminal device using the frequency band f3. Note that the channel quality described in this embodiment is, for example, communication generated based on received signal quality (received SINR (Signal to Interference and Noise Ratio), received power, etc.) measured by the terminal device. Information indicating whether or not the frequency band can be used.

  In FIG. 1, the reception control unit 20 of the terminal device includes a frequency band f1 reception unit 21-1, a frequency band f2 reception unit 21-2, a frequency band f3 reception unit 21-3, and a signal detection / measurement unit. 22, a channel quality transmission unit 23, and a frequency band management unit 24. The signal detection / measurement unit 22 includes a signal detection unit 22-1 and a received signal quality measurement unit 22-2.

  The frequency band f1 receiver 21-1 receives a control signal or a data signal of the frequency band f1. The frequency band f2 receiving unit 21-2 receives a control signal or a data signal of the frequency band f2. The frequency band f3 receiving unit 21-3 receives the control signal or data signal of the frequency band f3. The signal detector 22-1 detects control information or data from the received signal. The reception signal quality measurement unit 22-2 measures the reception signal quality for each reception unit based on, for example, pilot signals received by the reception units (21-1, 21-2, 21-3). The channel quality transmission unit 23 generates channel quality to be described later based on the reception signal quality measured by the reception quality measurement unit 22-2, and transmits the channel quality to the base station apparatus. The frequency band management unit 24 selects a reception unit that receives a signal based on the frequency band allocated by the frequency allocation control by the base station apparatus.

  The reception signal quality measurement unit 22-2 may receive a pilot signal over a long period of time or in a wide band, perform measurement a plurality of times, and use an average value obtained from a plurality of measurement values as reception signal quality. Thereby, it is possible to obtain a measurement value mainly including the influence of shadowing in which the influence of instantaneous multipath fading is reduced.

  Next, propagation characteristics due to differences in frequency bands in the multiband wireless communication system will be described. FIG. 3 is a diagram illustrating the propagation characteristics depending on the frequency band. Here, a case where the base station apparatus 1 and the terminal apparatuses 2 and 3 perform communication using two frequency bands f1 and f2 is shown. The base station device 1 and the terminal devices 2 and 3 are assumed to have the functions described above.

  Usually, propagation characteristics in wireless communication vary depending on the frequency band, and the range in which services can be provided also varies depending on the frequency band. For example, a low frequency band with a large wavelength has a large amount of radio waves, and it is easy to communicate even in an out-of-sight environment or an indoor environment. Therefore, it is possible to provide a service over a wider range by using a low frequency band in mobile communication. On the other hand, as the frequency band becomes higher, the straightness of the radio wave becomes stronger, and the stability of the wireless connection is deteriorated particularly in an out-of-sight environment. Here, the line-of-sight environment refers to a state where there is no shielding object on a straight line connecting the devices, and the non-line-of-sight environment refers to a state where the shielding object exists on a straight line connecting the devices.

  For example, in FIG. 3, the terminal device 2 that is in the line-of-sight environment as viewed from the base station device 1 can communicate with the base station device 1 in any of the low frequency band f1 and the high frequency band f2. Is possible. On the other hand, the terminal device 3 that is in a non-line-of-sight environment as viewed from the base station device 1 can communicate with the base station device 1 in the low frequency band f1, but can communicate with the base station device 1 in the high frequency band f2. Cannot communicate with each other. Therefore, for example, for a wireless communication system such as a cellular system, communication using the low frequency band f1 that can provide a wide range of services is suitable. However, even if the base station device 1 tries to assign a plurality of terminal devices to a low frequency band, if the number of terminal devices is large, it may not be possible to assign all the terminal devices to a low frequency band. Therefore, the base station apparatus 1 realizes control of preferentially assigning a high frequency band to the terminal apparatus 2 in the line-of-sight environment and assigning a low frequency band to the terminal apparatus 3 in the non-line-of-sight environment. Is desirable.

  Subsequently, characteristic processing of the present embodiment will be described. FIG. 4 is a diagram illustrating an example of a table for storing information (channel quality) indicating whether or not the frequency band is usable for communication. Here, as an example, it is assumed that the terminal device 2 and the base station device 1 communicate with each other. FIG. 4 shows a conventional table (FIG. 4A) and a table according to the present embodiment (FIG. 4B). These tables are composed of a bit number, a frequency band f1, a frequency band f2, and a frequency band f3. The bit number is a number uniquely associated with the channel quality transmitted from the terminal device 2 to the base station device 1. The frequency band f1 indicates whether or not the frequency band f1 can be used for communication between the terminal device 2 and the base station apparatus 1. For example, “1” indicates that the received signal quality in the frequency band f1 satisfies the reference value determined in advance by the terminal device 2 and can be used. On the other hand, “0” indicates that the received signal quality in the frequency band f1 is not usable because the terminal device 2 does not satisfy the predetermined reference value. Further, “*” represents either “0” or “1” (represents that it is not necessary to specify). Note that the terminal device 2 can arbitrarily set a reference value of the received signal quality for determining whether or not the frequency band can be used, and can also change the reference value. Further, the frequency band f2 and the frequency band f3 are defined similarly to the frequency band f1. The table of this embodiment shown in FIG. 4B is managed by the channel quality transmission unit 23 of the terminal device 2 and the channel quality reception unit 11 of the base station device 1.

For example, since a conventional terminal device transmits information indicating whether or not each frequency band is a frequency band that can be used for communication, if there are L frequency bands, bits necessary for transmission of channel quality The number is L bits (bit numbers 1 to 2 ^L ) including when the entire frequency band cannot be used. For example, when there are three frequency bands (L = 3), 3 bits (bit numbers 1 to 8) are required to transmit the channel quality.

  On the other hand, in this Embodiment, the terminal device 2 transmits only the information (bit number) of the highest frequency band which can be used for communication to the base station apparatus 1 as channel quality. In the multi-band method, since the propagation characteristics are poor in the high frequency band, the base station apparatus 1 allocates as high a frequency band as possible in an environment where the terminal apparatus 2 can use the high frequency band, and the high frequency band for the low frequency band. It is desirable to assign it to other communication devices that cannot communicate with each other. Therefore, in the present embodiment, the terminal device 2 transmits only information (the channel quality of the present embodiment) indicating the highest frequency band available for communication to the base station device 1. Thereby, the number of bits required for transmission of channel quality can be reduced as compared with the case of transmitting information of all frequency bands as in the conventional case.

For example, when the terminal device 2 transmits the channel quality of bit number 3, since the highest frequency band available for communication is the frequency band f3, the frequency bands f2 and f1 lower than the frequency band f3 can be used. It is not specified whether or not. Therefore, the number of bits necessary for the terminal apparatus 2 to transmit the channel quality is “log ₂ (L + 1)” including the case where the entire frequency band cannot be used. For example, when there are three frequency bands (L = 3), the necessary number of bits is “log ₂ (3 + 1) = 2” bits (bit numbers 1 to 4), and the conventional three bits (bit numbers 1 to 8) are used. ), The number of bits can be reduced. Further, in the present embodiment, as the number L of frequency bands increases, the reduction range of the number of bits necessary for transmission of channel quality can be increased as compared with the conventional case.

  Further, in the channel quality notification process, it can be said that the terminal device 2 groups channel quality combinations in each frequency band. For example, the information represented by the bit number: 3 in the table of the present embodiment shown in FIG. 4B has four types of bit numbers: 2, 4, 6, 8 in the conventional table shown in FIG. Information is grouped into one.

  Further, as described above, in the multiband wireless communication system that performs communication using the highest available frequency band, the base station apparatus 1 is based on the table of this embodiment (FIG. 4B). Even when the channel quality is received, the frequency band that can be used for communication can be obtained as in the conventional case. Therefore, the same frequency as when the channel quality is received based on the conventional table (FIG. 4 (a)). Allocation control can be realized. That is, in the present embodiment, it is possible to reduce the number of bits of channel quality transmitted from terminal apparatus 2 to base station apparatus 1 without degrading the performance of frequency allocation control.

  In the above description, as a method for reducing the number of bits of channel quality transmitted by the terminal device 2, the case where the channel quality of a lower frequency band is not transmitted when a high frequency band is available has been described. However, the present invention is not limited to this. For example, assuming that the highest frequency band cannot be allocated to the terminal device 2, the terminal device 2 has one or more frequencies in order from the highest frequency band among the frequency bands available for communication. The band may be selected and the information may be transmitted to the base station apparatus 1 as channel quality. As a transmission method, without using the table shown in FIG. 4B, for example, an “ID number” uniquely corresponding to each frequency band is assigned in advance, and the frequency band is specified using the “ID number”. Then send.

  In the above description, the base station apparatus performs frequency allocation control so that communication is performed using the highest available frequency band. However, communication is performed using the lowest available frequency band. It is also possible to perform frequency allocation control so that. For example, when the terminal device 2 performs communication requiring high reliability such as voice communication, the base station device 1 preferentially assigns the terminal device 2 from a low frequency band. And it allocates from a high frequency band with respect to the other terminal device which performs the data communication which a delay is permitted. In this case, the terminal device 2 that performs voice communication transmits information indicating the lowest frequency band available for communication to the base station device 1 as channel quality.

  As described above, according to the present embodiment, according to the frequency allocation control policy by the base station apparatus 1, that is, in the case of preferential allocation from a high frequency band and the case of preferential allocation from a low frequency band. Accordingly, the frequency band to be preferentially transmitted as the channel quality by the terminal device 2 is changed. The frequency allocation control policy by the base station apparatus 1 can be defined in advance for the entire system. Further, as a whole system, it is possible to change the frequency band to be preferentially transmitted by changing the frequency allocation control policy for each base station device, for each time, for each terminal device, or for each communication. As a method of changing the frequency allocation control policy, for example, the base station apparatus 1 transmits in advance to a terminal apparatus in the communication area by a control signal. The terminal device in the communication area transmits information indicating the frequency band to be preferentially transmitted based on the content of the control signal as the channel quality.

  Further, the terminal device 2 can autonomously select a specific frequency band from the available frequency bands and transmit the frequency band to the base station apparatus 1 as channel quality. Thereby, the terminal device 2 can transmit appropriate channel quality according to the type (for example, voice communication, data communication, etc.) of communication performed by the terminal device 2 and the required level (for example, importance level). .

  As described above, in the present embodiment, the terminal apparatus preferentially selects at least one frequency band from the frequency bands available for communication, and bases information on the frequency band as channel quality. It was decided to transmit to the station equipment. As a result, the amount of channel quality information can be greatly reduced as compared with the prior art that transmits information of all frequency bands (whether they can be used) regardless of whether they can be used for communication. In the present embodiment, the base station apparatus receives the channel quality having the information amount greatly reduced. This makes it possible to easily recognize the frequency band to be used preferentially by the terminal device, so that the frequency allocation control equivalent to the conventional one can be easily realized even though the amount of channel quality information is reduced. can do.

Embodiment 2. FIG.
In this Embodiment, the information regarding the reception quality of the frequency band which can be utilized for communication produced | generated based on the received signal quality which the terminal device measured is transmitted as channel quality. As an example, the terminal device displays an ID indicating the highest available frequency band and information on the level of received signal quality in the frequency band (information indicating which range the received signal quality belongs to) as channel quality. To the base station apparatus. In the present embodiment, processing different from that of the first embodiment will be described.

  FIG. 5 is a diagram illustrating a configuration example of the multiband radio communication system according to the present embodiment. Specifically, the transmission control unit 10a in the base station apparatus and the terminal apparatus in the multiband radio communication system are included. It is a figure which shows each structural example of the reception control part 20a of. In addition, about the structure similar to Embodiment 1 mentioned above, the same code | symbol is attached | subjected and the description is abbreviate | omitted.

  In FIG. 5, the transmission control unit 10a of the base station apparatus includes a channel quality reception unit 11a and a frequency band management unit 12a. In this embodiment, for convenience of explanation, four discontinuous frequency bands of f1, f2, f3, and f4 are used. The magnitudes of the frequency bands f1, f2, f3, and f4 have a relationship of f1 <f2 <f3 <f4. Therefore, in the present embodiment, a frequency band f4 transmission unit 14-4 that newly transmits a control signal or a data signal to the terminal device using the frequency band f4 is newly provided.

  The channel quality receiving unit 11a receives channel quality (to be described later) from the terminal device and transfers it to the frequency band management unit 12a. When a communication request is received from a specific terminal device, the frequency band management unit 12a performs frequency allocation control based on the channel quality of the present embodiment obtained from the terminal device.

  In FIG. 5, the reception control unit 20a of the terminal device includes a channel quality transmission unit 23a. The channel quality transmission unit 23a generates channel quality to be described later based on the reception signal quality measured by the reception quality measurement unit 22-2, and transmits the channel quality to the base station apparatus. In the present embodiment, since the frequency band f4 is used as described above, the frequency band f4 receiving unit 21-4 that receives the control signal or data signal of the frequency band f4 is newly provided.

  FIG. 6 is a diagram showing an example of frequency bands that can be used in the multiband wireless communication system according to the present embodiment, a frame format of channel quality, and a table of received signal quality. In this embodiment, an ID number is assigned to each frequency band.

  A channel quality frame is composed of an ID number and a bit number. An ID number representing the highest available frequency band is assigned to the ID number. For example, when the highest available frequency band is f3, ID number: ID = 3 corresponding to the frequency band f3 is assigned. Further, a bit number corresponding to the level of received signal quality in the highest available frequency band is assigned to the bit number. In the present embodiment, average received SINR is adopted as an example of received signal quality, and a bit number (refer to a table) corresponding to the level of average received SINR in the highest available frequency band is given.

  The received signal quality table is composed of bit numbers and average received SINRs. For example, bit numbers: 0 and “SINR <−3”, bit numbers: 1 and “−3 ≦ SINR <−2”,. It is associated.

  In the present embodiment, since the terminal device transmits only the information related to the reception quality of the highest frequency band that can be used for communication as the channel quality to the base station device, information on all frequency bands (whether it can be used or not) Compared with the conventional technology for transmission, the amount of information required for transmission of channel quality can be greatly reduced.

  In the base station apparatus, the channel quality receiving unit 11a receives the channel quality generated above, and the frequency band managing unit 12a obtains the highest available frequency band and average received SINR obtained from the channel quality. Based on this, frequency allocation control was performed. As a result, it is possible to accurately determine the modulation scheme, coding rate, throughput, and the like used for communication with the terminal device, and to improve the accuracy of frequency allocation control by using the result for frequency allocation control. it can.

Embodiment 3 FIG.
In Embodiment 2, the terminal apparatus transmits information on the reception quality of the highest frequency band available for communication as channel quality to the base station apparatus. However, the base station apparatus may not be able to allocate the communication request transmission source terminal apparatus to the highest frequency band that the terminal apparatus can use for communication. Therefore, in the present embodiment, as an example, the terminal device transmits information on received signal quality of two frequency bands as channel quality. Specifically, the terminal device bases an ID indicating the highest frequency band that can be used, information on a received signal quality level in that frequency band, and information on a received signal quality level in the next highest frequency band. Send to station device. In the present embodiment, processing different from that of the second embodiment will be described. The apparatus configuration is the same as that of FIG. 5 of the second embodiment described above.

  FIG. 7 is a diagram showing an example of frequency bands that can be used in the multiband radio communication system according to the present embodiment, a frame format of channel quality, and a table of received signal quality. The bit number # 1 of the channel quality frame is the same as the bit number (see FIG. 6) in the second embodiment. Bit number # 2 is assigned a bit number corresponding to the level of received signal quality in the next highest frequency band after the highest available frequency band.

  For example, when the highest available frequency band is the frequency band f3, the ID number and the bit number # 1 assigned to the channel quality frame are the same as those in the second embodiment, and the bit number # 2 includes the frequency band f3. A bit number (see the table) corresponding to the level of the average received SINR in the next highest frequency band f2 is assigned.

  In this embodiment, since the terminal device transmits only the information on the highest frequency band available for communication and the next highest frequency band to the base station device as channel quality, information on all frequency bands (available for use) The amount of information required for transmission of channel quality can be greatly reduced compared to the prior art that transmits whether or not.

  In the base station apparatus, the channel quality reception unit 11a receives the channel quality generated above, and the frequency band management unit 12a performs frequency allocation control based on the channel quality. Thereby, since the base station apparatus can be made into the candidate which allocates two frequency bands to a terminal device, the probability that a frequency band cannot be allocated with respect to a terminal device can be reduced. Compared with Embodiment 2, the information amount of channel quality increases, but better frequency allocation control can be realized.

  In the above description, a case has been described in which the terminal apparatus transmits information indicating the received signal quality levels of the two frequency bands, but the received signal quality level of one frequency band (for example, frequency band f2) is transmitted. The information can also be transmitted as difference information for the received signal quality of the other frequency band (for example, frequency band f3), for example.

  FIG. 8 is a diagram illustrating an example of a frequency band that can be used in the multiband wireless communication system according to the present embodiment, a channel quality frame format, a received signal quality table, and a received signal quality difference table. In this case, bit number # 2 is assigned a bit number corresponding to the difference between the average received SINR of the highest available frequency band and the average received SINR of the next highest frequency band.

  The received signal quality difference table is composed of bit number and average received SINR difference. For example, bit number: 0 and “SINR difference <−9”, bit number: 1 and “−9 ≦ SINR difference <−6”. Are associated with each other.

  Normally, in the terminal device, the received signal quality (average received SINR) of adjacent frequency bands (here, frequency band f2 and frequency band f3) has a high correlation with each other. Therefore, the terminal device transmits the information of the average received SINR of one frequency band as difference information and includes it in the channel quality, so that the number of bits necessary for transmission of the channel quality can be reduced to the two frequency bands described above. The received signal quality level information can be reduced as compared with the case of transmitting and indicating each of the received signal quality level information. As a result, the amount of information required for transmission of channel quality can be further reduced as compared with the conventional technique that transmits information (whether it can be used) in all frequency bands.

  Also, the terminal device has an ID for identifying the highest available frequency band and a number (U) indicating how many frequency bands are available in the direction from the frequency band to the lower frequency band. May be simultaneously transmitted to the base station apparatus. Thereby, the base station apparatus can make U frequency bands continuous from the highest available frequency band as candidates to be allocated to the terminal apparatus.

Embodiment 4 FIG.
In the present embodiment, a case will be described in which the terminal device transmits information on received power in the lowest frequency band and received power in the highest frequency band as channel quality. In the present embodiment, processing different from that in the second or third embodiment will be described. The apparatus configuration is the same as that of FIG. 5 of the second embodiment described above.

  FIGS. 9-1 and 9-2 are diagrams illustrating received power when the terminal apparatus receives pilot signals from the base station apparatus in four frequency bands. Specifically, FIG. FIG. 9B is a diagram illustrating received power in each frequency band in a non-line-of-sight environment (including an indoor environment). “P” represents the received power in the low frequency band f1. “Δ” represents the difference between the received power P in the lowest frequency band f1 and the received power in the highest frequency band f4.

  Normally, in the line-of-sight environment, the terminal device obtains strong received power in both the lowest frequency band f1 and the highest frequency band f4. On the other hand, in a non-line-of-sight environment, the received power is drastically decreased in the highest frequency band f4, and the variation (difference) in received power between the lowest frequency band f1 and the highest frequency band f4 increases.

  Whether the terminal device is in a line-of-sight environment or a non-line-of-sight environment in communication with the base station device by measuring variations in received power or a decrease in received power in each frequency band, Can be judged. Here, as an example, the terminal device obtains the variation in received power by calculating “Δ / P”. When the variation in received power is larger than a preset threshold value, the terminal device determines that there is a high possibility that the terminal device is located in an environment outside the line-of-sight.

  In this way, the terminal device can recognize the position of the device itself or the surrounding environment by obtaining the variation in received power. In addition to the received power variation information, the terminal device can use the information obtained from the GPS and other location information services to obtain the location of the device with higher accuracy. Note that the terminal device can arbitrarily set a threshold value for determining that the terminal device is located in a non-line-of-sight environment, and can also change the threshold value.

  In the present embodiment, since the terminal device transmits information on the variation in received power to the base station device as channel quality, it is compared with the conventional technology that transmits information (whether it can be used) in all frequency bands. Thus, the amount of information required for transmission of channel quality can be greatly reduced.

  In the base station apparatus, the channel quality reception unit 11a receives the channel quality generated above, and the frequency band management unit 12a performs frequency allocation control based on the channel quality. As a result, it is possible to determine whether the terminal device is in the non-line-of-sight environment or the line-of-sight environment, and the result can be used for frequency allocation control. For example, when the base station apparatus determines that the terminal apparatus is in the non-line-of-sight environment, the base station apparatus can allocate the lowest frequency band f1 to the terminal apparatus. Further, when the base station apparatus determines that the terminal apparatus is in the line-of-sight environment, the base station apparatus can allocate the highest frequency band f4 to the terminal apparatus.

  In addition, the base station apparatus can provide a more accurate position information service to the terminal apparatus as a whole system by grasping the position of the terminal apparatus in detail. The base station apparatus can improve position estimation accuracy comprehensively by simultaneously using various pieces of position related information other than variations in received power.

  In addition, information regarding variations in received power or the degree of decrease in received power in each frequency band can be used for many other purposes. For example, the terminal device can predict received power in other frequency bands if information on received power in a specific frequency band and variations in received power are obtained. Normally, the received power monotonously decreases as the frequency band becomes higher, so the terminal device predicts the received power in multiple frequency bands by approximating the relationship between the frequency band and the received power with an appropriate linear or nonlinear curve. it can. In this way, various effects can be obtained by measuring the variation in received power by the terminal device and transmitting it to the base station device.

  As described above, the multiband wireless communication system according to the present invention is useful for a wireless communication system including a base station device and a terminal device, and is particularly suitable when the terminal device transmits channel quality.

It is a figure which shows the structural example of the transmission control part of a base station apparatus, and the reception control part of a terminal device. It is a figure which shows an example of the frequency band which can be used in a multiband radio | wireless communications system. It is a figure which shows the propagation characteristic by the difference in a frequency band. It is a figure which shows an example of the table for storing the information which shows whether it is a frequency band which can be used for communication. It is a figure which shows the structural example of the transmission control part of a base station apparatus, and the reception control part of a terminal device. It is a figure which shows an example of the frequency band which can be used in a multiband radio | wireless communications system, the frame format of channel quality, and the table of received signal quality. It is a figure which shows an example of the frequency band which can be used in a multiband radio | wireless communications system, the frame format of channel quality, and the table of received signal quality. It is a figure which shows an example of the frequency band which can be used in a multiband radio | wireless communications system, the frame format of channel quality, the table of received signal quality, and the table of the difference of received signal quality. It is a figure which shows the received power of each frequency band in a line-of-sight environment. It is a figure which shows the received power of each frequency band in a non-line-of-sight environment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Base station apparatus 2 Terminal apparatus 3 Terminal apparatus 10, 10a Transmission control part 11, 11a Channel quality receiving part 12, 12a Frequency band management part 13 Signal generation part 14-1 Frequency band f1 transmission part 14-2 Frequency band f2 transmission part 14-3 Frequency band f3 transmitter 14-4 Frequency band f4 transmitter 20, 20a Reception control unit 21-1 Frequency band f1 receiver 21-2 Frequency band f2 receiver 21-3 Frequency band f3 receiver 21-4 Frequency Band f4 reception unit 22 Signal detection / measurement unit 22-1 Signal detection unit 22-2 Received signal quality measurement unit 23, 23a Channel quality transmission unit 24 Frequency band management unit

Claims (25)

A multi-band wireless communication system configured with a base station device and a terminal device under the base station device and performing communication using a plurality of discontinuous frequency bands,
The terminal apparatus selects at least one frequency band from among frequency bands available for communication, and transmits information on the frequency band to the base station apparatus as channel quality,
When the base station apparatus receives a communication request from a specific terminal apparatus, the base station apparatus performs frequency allocation control on the terminal apparatus based on the channel quality received from the terminal apparatus. system.   The multiband radio communication system according to claim 1, wherein the terminal apparatus appropriately changes a frequency band to be preferentially selected according to a frequency allocation control policy by the base station apparatus.   The multiband wireless communication system according to claim 2, wherein the policy can be defined as a system.   The multi-band wireless communication system according to claim 2, wherein the policy can be changed in units of a base station device, time, a terminal device, or communication. The policy is to preferentially assign the highest frequency band available for communication;
The terminal device transmits information on the highest frequency band available for communication as channel quality to the base station device,
The base station apparatus allocates the highest frequency band that can be used for communication to a specific terminal apparatus that is the communication request source based on the received channel quality. A multiband wireless communication system according to claim 1.   The multi-band wireless communication system according to claim 2, 3 or 4, wherein the policy is to preferentially assign a lowest frequency band available for communication.   Assuming the case where the highest frequency band cannot be allocated, the terminal device selects a plurality of frequency bands in order from the highest frequency band available for communication, and stores information on the selected plurality of frequency bands. 6. The multiband radio communication system according to claim 5, wherein channel quality is transmitted to the base station apparatus.   The multiband radio communication system according to any one of claims 1 to 7, wherein information regarding the frequency band to be transmitted as the channel quality is information indicating that it can be used.   The multiband radio communication system according to any one of claims 1 to 6, wherein the information about the frequency band transmitted as the channel quality is information about the received signal quality measured by the terminal device. The policy is to preferentially assign the highest frequency band available for communication;
Assuming the case where the highest frequency band cannot be allocated, the terminal apparatus uses the information on the highest frequency band available for communication and the information on the next highest frequency band as channel quality as the base station apparatus. Send to
The base station apparatus uses the two frequency bands included in the received channel quality as frequency band candidates to be allocated to the specific terminal apparatus that is the communication request source. The multiband wireless communication system described.   The information on the highest frequency band and the information on the next highest frequency band to be transmitted as the channel quality are information on received signal quality measured by the terminal apparatus. Band radio communication system.   As information to be transmitted as the channel quality, information on the highest frequency band is information on received signal quality measured by the terminal device, and information on the next highest frequency band is difference information with the received signal quality. The multiband radio communication system according to claim 10. A multi-band wireless communication system configured with a base station device and a terminal device under the base station device and performing communication using a plurality of discontinuous frequency bands,
When the terminal apparatus receives a known signal from the base station apparatus in the plurality of frequency bands, the received power of the known signal in the lowest frequency band and the received power of the known signal in the highest frequency band are Send to the base station device as quality,
When the base station apparatus receives a communication request from a specific terminal apparatus, the base station apparatus performs frequency allocation control on the terminal apparatus based on the channel quality received from the terminal apparatus. system.   The multiband wireless communication according to claim 13, wherein the terminal device determines whether the terminal device is located in a line-of-sight environment or an outside line-of-sight environment based on the received power. system.   When the base station device determines that the terminal device is located in the line-of-sight environment based on the received channel quality, the base station device allocates the highest frequency band to the terminal device, while the terminal device is located in the non-line-of-sight environment. The multiband radio communication system according to claim 13 or 14, wherein, when judged, the lowest frequency band is assigned to the terminal device. When a communication request is received from a specific terminal device, a wireless communication system is configured together with a wireless base station that performs frequency allocation control on the terminal device based on the channel quality received from the terminal device. A terminal device that communicates with the base station device using a frequency band,
A terminal apparatus, wherein at least one frequency band is selected from frequency bands available for communication, and information relating to the frequency band is transmitted as channel quality to the base station apparatus.   The terminal apparatus according to claim 16, wherein information on the highest frequency band available for communication is transmitted as channel quality to the base station apparatus.   Assuming the case where the highest frequency band cannot be allocated, a plurality of frequency bands are selected in order from the highest frequency band available for communication, and the information regarding the selected frequency band is used as the channel quality as the base station apparatus. The terminal device according to claim 17, wherein the terminal device is transmitted to the terminal device.   19. The terminal apparatus according to claim 16, 17 or 18, wherein information indicating that the frequency band transmitted as the channel quality is usable.   The terminal apparatus according to claim 16 or 17, wherein information on the frequency band transmitted as the channel quality is information on received signal quality measured by the terminal apparatus.   The terminal apparatus according to claim 16, wherein information on the highest frequency band available for communication and information on the next highest frequency band are transmitted to the base station apparatus as channel quality.   The terminal according to claim 21, wherein the information on the highest frequency band and the information on the next highest frequency band transmitted as the channel quality are information on the received signal quality measured by the terminal apparatus. apparatus.   As information to be transmitted as the channel quality, information on the highest frequency band is information on received signal quality measured by the terminal device, and information on the next highest frequency band is difference information with the received signal quality. The terminal device according to claim 21, wherein: When a communication request is received from a specific terminal device, a wireless communication system is configured together with a wireless base station that performs frequency allocation control on the terminal device based on the channel quality received from the terminal device. A terminal device that communicates with the base station device using a frequency band,
When a known signal is received from the base station apparatus in the plurality of frequency bands, the received power of the known signal in the lowest frequency band and the received power of the known signal in the highest frequency band are used as the channel quality as the base station. A terminal device that transmits to a device.   25. The terminal device according to claim 24, wherein it is determined whether the device is located in a line-of-sight environment or a non-line-of-sight environment based on the received power.

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