JP5289486B2 - Radio base station apparatus, radio unit control apparatus, and radio communication method - Google Patents

Description

  Embodiments described herein relate generally to a radio base station apparatus, a radio unit control apparatus, and a radio communication method that perform radio communication with a radio terminal.

  2. Description of the Related Art In recent years, mobile radio communication systems have been advanced and speeded up, and studies have been conducted on the realization of radio communication having a theoretical speed exceeding 100 Mbps in communication systems such as WiMAX, LTE, and XGP systems. As a technology for realizing high-speed wireless communication, there is a MIMO (Multiple Input Multiple Output) technology in which a base station has a plurality of antennas and performs communication multiplexing with a terminal by performing spatial multiplexing. Application to the next generation mobile radio communication system is being studied.

  However, MIMO is expected to improve the speed at the center of the cell, but communication degradation near the cell edge has been a problem. Therefore, studies on macro diversity that improves the reception power of terminals using antennas of different base stations are being promoted, and are regarded as important techniques for improving the gain of terminals existing in the vicinity of the cell edge. In macro diversity, in order to improve the gain of a terminal by communication using a plurality of base stations, antenna control and a communication method across base stations are essential.

JP-A-8-256162

  An object of the present embodiment is to provide a radio base station apparatus, a radio unit control apparatus, and a radio communication method that can improve the communication quality of terminals near the cell edge.

  The radio base station apparatus according to the present embodiment includes a plurality of antennas, and a plurality of radio units that perform radio communication with the radio terminals using the antennas, and reception power of uplink signals from the radio terminals for each antenna. A measurement means for measuring the information, a creation means for creating information representing a combination of antennas used for macro diversity communication by the plurality of wireless units with the wireless terminal, a combination of the measurement result of the received power and the antenna Selection means for selecting a combination of antennas to be used for the wireless communication based on information representing the signal, and signal processing means for performing wireless control of the plurality of wireless units according to the combination of antennas selected by the selection means; , Macro diversity in which the signal quality of the macro diversity communication is associated with the combination of the antennas Comprising a means for storing the gravel information, the creation means is to update the information representative of the combination of the antenna on the basis of the macro-diversity history information.

  A radio unit control apparatus according to the present embodiment is a radio unit control apparatus that includes a plurality of antennas and controls a plurality of radio units that perform radio communication with a radio terminal using the antennas. Measuring means for measuring the received power of the uplink signal for each antenna; creating means for creating information representing a combination of antennas used for macro diversity communication by the plurality of wireless units with the wireless terminal; and Selection means for selecting a combination of antennas used for the wireless communication based on a measurement result of received power and information indicating the combination of the antennas, and the plurality of radios according to the combination of antennas selected by the selection means Signal processing means for performing wireless control of a unit, signal quality of the macro diversity communication and a combination of the antennas, Comprising a means for storing the macro diversity history information correlating the creation means is configured to update the information representative of the combination of the antenna on the basis of the macro-diversity history information.

  The wireless communication method according to the present embodiment is a wireless communication method used for a wireless unit control apparatus that includes a plurality of antennas and controls a plurality of wireless units that perform wireless communication with a wireless terminal using the antennas. Measuring the reception power of the uplink signal from the wireless terminal for each antenna, and creating information representing a combination of antennas used for macro diversity communication by the plurality of wireless units with the wireless terminal Selecting a combination of antennas to be used for the wireless communication based on the measurement result of the received power and information indicating the combination of the antennas, and the plurality of wireless units according to the selected combination of antennas Performing radio control of the above, and associating the signal quality of the macro diversity communication with the combination of the antennas And a to accumulate black diversity history information, in that the creation, it is to update the information representative of the combination of the antenna on the basis of the macro-diversity history information.

The whole block diagram of a radio | wireless communications system provided with the radio base station apparatus which concerns on this embodiment. The block diagram which shows the structure of the wireless base station apparatus of FIG. The figure which shows the creation process of macro diversity history information. The figure which shows the creation process of handover history information. The figure which shows the creation process of antenna combination information. The figure which shows a received power measurement process. The figure which shows a macro diversity availability determination process. The figure which shows a macro diversity use antenna selection process. The figure which shows a macro diversity communication process. The figure which shows an antenna switching evaluation result. The figure which shows the creation sequence of adjacent radio | wireless part information and antenna combination information. The figure which shows a macro diversity communication start sequence.

  The radio base station apparatus, radio unit control apparatus, and radio communication method according to the present embodiment will be described below with reference to the drawings.

[System configuration]
FIG. 1 is an overall configuration diagram of a radio system including a radio base station apparatus according to the present embodiment. In the present embodiment, the radio unit and the control unit of the conventional base station are separated, and macro diversity is realized by a base station form in which the control units are aggregated.

  In FIG. 1, an IP network / public communication network NW is connected to the gateway device GW, and a plurality of radio base station devices BS1 and BS2 are connected to the gateway device GW. The radio base station apparatus BS1 includes a plurality of radio units R11 to R1n that perform radio transmission and reception, and a radio unit control device G1 that performs signal processing and signal distribution related to radio. Wireless terminal devices MS11 to MS1m such as wireless terminals or PCs (personal computers) equipped with wireless communication data cards perform voice or data communication with the wireless units R11 to R1n. Each of the radio units R11 to R1n includes a plurality of antennas, and can adjust the transmission power of the plurality of antennas to give directivity to the downlink signal. Similarly to the radio base station device BS1, the radio base station device BS2 includes a radio unit control device G2 and a plurality of radio units R21 to R2n that perform radio communication with the radio terminal device.

[Device configuration]
FIG. 2 is a block diagram illustrating an example of a configuration of the radio base station apparatus. Below, radio base station apparatus BS1 is demonstrated as a representative.

  In FIG. 2, the gateway device GW is connected to the IP network / public communication network NW and the wireless unit control device G1, and the wireless unit control device G1 and the plurality of wireless units R11 and R12 are connected by wires such as optical fibers, for example. The The wireless unit R11 is provided with a plurality of antennas AN11 to AN1n for wireless communication with the wireless terminal devices MS11 and MS12. Similarly, the wireless unit R12 is also provided with a plurality of antennas AN21 to AN2n for wireless communication.

  The wireless terminal devices MS11 and MS12 and the wireless units R11 and R12 are provided with a wireless communication unit 101, and the wireless terminal devices MS11 and MS12 perform wireless communication with one or more wireless units by the wireless communication unit 101. The wireless unit control device G1 includes a signal distribution unit 102 that distributes data received from the gateway device GW to the wireless units R11 and R12 that perform wireless communication with the wireless terminal devices MS1 and MS2, and a signal that performs control related to wireless communication. A processing unit 103 is provided.

  The wireless terminal devices MS11 and MS12 and the wireless units R11 and R12 are provided with a wireless communication unit 101, and the wireless terminal devices MS11 and MS12 perform wireless communication with one or more wireless units by the wireless communication unit 101. The wireless unit control device G1 includes a signal distribution unit 102 that distributes data received from the gateway device GW to the wireless units R11 and R12 that perform wireless communication with the wireless terminal devices MS1 and MS2, and a signal that performs control related to wireless communication. A processing unit 103 is provided.

  The signal processing unit 103 has a role of controlling the signal processing of the radio units R11 and R12. Here, a plurality of signal processing units 1031 and 1032 are provided according to the number of radio units R11 and R12. However, the present invention is not limited to this, and one signal processing unit 103 can control a plurality of radio units, and the number of radio units and the number of signal processing units are allowed to be different values.

  The radio unit controller G1 transmits the uplink data received from the radio terminals MS1 and MS2 via the radio units R11 and R12 to the IP network / public communication network NW via the gateway unit GW. Also, downlink data received from the IP network / public communication network NW via the gateway device GW is distributed to an appropriate radio unit by the signal distribution unit 102, and the radio terminal devices MS11, MS12 are transmitted via the radio units R11, R12. Send to.

  Further, the radio unit controller G1 includes a received power measuring unit 104, a received power aggregation information storage unit 105, a history information management unit 106, a macro diversity history information storage unit 107, a handover history information storage unit 108, an antenna information creation unit 109, An antenna combination information storage unit 110 and an antenna selection unit 111 are provided.

  Received power measuring section 104 measures the received power of uplink signals from radio terminal apparatuses MS1 and MS2 for each antenna of each radio section, and receives received power as aggregated information (received power aggregate information). Stored in the aggregate information storage unit 105.

  The history information management unit 106 associates and stores the antenna combination and communication quality information in the past macro diversity communication of the radio units R11 and R12 in the macro diversity history information storage unit 107. Further, the history information management unit 106 stores information representing the history of the wireless unit combinations connected by the handover performed in the past in the handover history information storage unit 108.

  The antenna information creation unit 109 creates information (antenna combination information) representing the antenna combination based on the information stored in the macro diversity history information storage unit 107 and each handover history information storage unit 108, and the antenna combination information Store in the storage unit 110. Based on the information stored in the received power aggregate information storage unit 105 and the antenna combination information storage unit 110, the antenna selection unit 111 includes the antennas AN11 to AN1n of the radio unit R11 and the antennas AN21 to AN2n of the radio unit R12. To select a combination of antennas used for wireless communication with the wireless terminal device.

  The operation of the wireless unit control apparatus G1 configured as described above will be described below.

[Create macro diversity history information]
FIG. 3 shows an example of macro diversity history information creation processing.
In FIG. 3, a plurality of radio units R11 to R14 are connected to the radio unit controller G1, and macro diversity communication is performed on the terminal MS11 from the radio units R11 and R12 using the antennas AN13 and AN22. The history information management unit 106 of the radio unit control device G1 stores the antenna combination AN13 and AN22 used in communication with the antenna combination AN13 and AN22 in the macro diversity history information storage unit 107 when macro diversity communication is performed in R11 and R12. . As the communication quality information, for example, received power, throughput, and bit error rate are stored.

[Create handover history information]
FIG. 4 shows an example of processing for creating handover history information.
In FIG. 4, the terminal MS11 performs handover from the radio unit R13 to the radio unit R14. The history information management unit 106 of the radio unit control apparatus G1 collectively manages the radio unit combinations R13 and R14 to which the terminal MS11 before and after the handover was connected, and stores it in the handover history information storage unit 108. The handover history information stored in the handover history information storage unit 108 is used when creating antenna combination information as adjacent radio unit information.

[Create antenna combination information]
FIG. 5 shows an example of a process for creating antenna combination information.

  In FIG. 5, it is assumed that the radio unit R11 includes antennas AN11 to AN14 and the radio unit R12 includes antennas AN21 to AN24. The antenna information creation unit 109 of the radio unit controller G1 acquires adjacent radio unit information from the handover history information storage unit 108, acquires past communication quality from the macro diversity history information 107, and uses the antenna combination for macro diversity communication. To decide. For the wireless unit combination for which there is no information in the macro diversity history information storage unit 107, antenna determination is performed based on the instantaneous value of the received power measured by the received power measuring unit 104 without using the history information.

  The number of radio units that determine the combination of antennas depends on the upper limit number M of antennas capable of macro diversity, and determines antenna combination information for combinations that are less than or equal to the upper limit number of antennas. For example, when the antenna upper limit number M = 2, the antenna combination pattern is determined in consideration of the combination of two radio units. When the antenna upper limit number M = 3, the antenna combination pattern is determined in consideration of the combination of three radio units. FIG. 5 shows an example when M = 2. For the radio unit combinations R11 and R12 stored in the handover history information 108, the combination AN13 and AN21 having the highest received power is determined as the antenna combination information from the macro diversity history information 107 and stored in the antenna combination information storage unit 110. In the example of FIG. 5, the antenna combination with the highest received power is selected from the past macro diversity history information 107, but the average received power may be compared. Further, the communication quality evaluation index is not limited to the received power, but it is also possible to use throughput, bit error rate information, and the like.

[Macro diversity control]
Macro diversity communication between the wireless terminal device and the wireless unit measures the received power of the uplink signal of the wireless terminal device, determines whether macro diversity is possible based on the measurement result of the received power, and enables macro diversity. If it is determined, it is realized by determining the antenna combination to be used for macro diversity and performing transmission control.

[Received power measurement]
FIG. 6 shows an example of reception power measurement of an uplink signal of a wireless terminal device.

  In FIG. 6, a plurality of radio units R11 to R14 are connected to the radio unit controller G1. The reception power measurement unit 104 of the radio unit controller G1 measures the reception power of the uplink signal A11 omni-transmitted from the radio terminal device MS11 in each radio unit R11 to R14, and performs radio unit control on the reception power information IN11 to 14 Notify the antenna selection unit 111 of the device G1. In the example of FIG. 6, each of the radio units R11 to R14 has a plurality of antennas AN11 to AN14, AN21 to 24, AN31 to 34, and AN41 to 44. Therefore, reception power measurement is performed for each radio communication antenna of each radio unit. Do. Although FIG. 6 shows an example in which the number of antennas is four, the number of antennas depends on the wireless communication system.

[Judgment of macro diversity availability]
FIG. 7 shows an example of received power aggregation information and macro diversity availability determination included in the radio unit control apparatus.

  The antenna selection unit 111 notified of the received power information of each of the radio units R11 to R14 in FIG. 6 by the received power measuring unit 104 in the radio unit controller G1 aggregates the received power information IN11 to IN14, and collects the received power. The information is stored in the information storage unit 105. Further, when the received power information is stored in the received power aggregated information storage unit 105, corresponding radio unit information and antenna information are stored for each received power information, and sorting by received power is performed.

  Reception power threshold value information R is set in advance in the antenna selection unit 111 of the radio unit controller G1, and whether or not macro diversity is possible is determined using the reception power aggregation information and the reception power threshold value information R. FIG. 7 shows an example of macro diversity availability determination when the received power threshold information R = 50 dB.

  The antenna selection unit 111 of the radio unit controller G1 refers to the received power aggregation information in the received power aggregation information storage unit 105, and uses an antenna whose received power from the radio terminal device is larger than the received power threshold information R as a macro diversity candidate antenna. decide. When there are a plurality of antennas determined as macro diversity candidate antennas, the wireless terminal apparatus determines that macro diversity is possible and selects a macro diversity use antenna. If the macro diversity candidate antenna is a single antenna, it is determined that macro diversity is not possible, and communication is performed using a single antenna.

[Select antenna for macro diversity]
FIG. 8 shows an example of macro diversity use antenna selection using received power aggregation information.

  An upper limit value M of the number of antennas that can be macrodiversified is set in the antenna selection unit 111 of the radio unit control apparatus G1 in advance, and is used when selecting a macro diversity use antenna. FIG. 8 shows an example in which the upper limit value M = 2 of the number of antennas capable of macro diversity is shown. The upper limit value M indicates the software / hardware specifications of the wireless terminal device that implements macro diversity, and the software / hardware of the wireless unit. It is determined according to conditions such as the wear specifications and the adjacent state of the radio unit.

  When it is determined that the macro diversity is possible, the antenna selection unit 111 of the radio unit controller G1 determines the top n of the macro diversity candidate antennas as the use antenna candidates AN22 and AN14. The number n to be selected is the smaller one of the number of macro diversity candidate antennas and the upper limit M of the number of antennas capable of macro diversity. At this time, referring to the antenna combination information storage unit 110 for the radio units R11 and R12 determined to be capable of macro diversity, the antenna combinations determined as the use antenna candidates AN22 and AN14 are different from the predetermined antenna combination information. In this case, the antenna combinations AN13 and AN22 set in the antenna combination information storage unit 110 are modified to be used antennas. When antenna combination information does not exist in the antenna combination information storage unit 110, macro diversity communication is started with the antenna combination determined as a candidate for use antenna.

  In addition, when it is determined that the radio part combination R11 and R12 determined to be capable of macro diversity are not adjacent in the handover history information 108, the radio part combination R11 and R12 is newly added to the handover history information 108. Macro diversity is implemented, and the communication quality of the antenna combination and macro diversity communication is accumulated in the macro diversity history information 107.

[Macro diversity communication control]
FIG. 9 shows an example of communication by macro diversity.

  The antenna selection unit 111 of the radio unit controller G1 sends a signal distribution change instruction to the signal distribution unit 102 corresponding to the determined use antenna, and sends a use antenna change instruction to the signal processing units 1031 and 1032. Start macro diversity communication. The signal distribution change instruction sends different radio unit information to which the used antenna belongs as a parameter, and the use antenna change instruction sends antenna combination information used for macro diversity as a parameter. The signal distribution unit 102 distributes downlink data for the corresponding terminal to the signal processing units 1031 and 1032 of the plurality of wireless units to which the antenna belongs based on the plurality of pieces of wireless unit information included in the signal distribution change instruction. Send. Further, the signal processing units 1031 and 1032 control the downlink transmission power of each antenna for the radio unit used for macro diversity based on the antenna combination information included in the antenna change instruction, and are selected by the antenna selection unit 111 Transmission is performed from the use antennas AN13 and AN22 to the radio terminal MS11.

[Evaluation of macro diversity communication by switching antennas used]
FIG. 10 shows an example of macro diversity communication evaluation by switching the antenna used.

  The antenna selection unit 111 of the radio unit control apparatus G1 performs macro diversity communication in which the antenna used is switched at a constant period T when the macro diversity communication is performed, and associates the antenna combination with the evaluation result of the communication quality so as to associate the macro diversity history information 107. To accumulate. The antenna to be switched to is an antenna adjacent to the antenna used for macro diversity communication. In the example of FIG. 10, antenna switching is performed by using AN11 and AN14 adjacent to the antenna AN13 in the radio unit R11 and AN21 and AN24 adjacent to the AN22 in the radio unit R12 as selection ranges.

  As a result of antenna switching, when antenna combinations AN13 and AN21 having higher communication quality than the current antenna combinations AN13 and AN22 are found, macro diversity with the new antenna combination is continued, and the antenna switching target range is changed to the antenna AN13 in the radio unit R11. In the adjacent AN11 and AN14 and the radio unit R12, the antennas used are switched at a constant cycle T as the AN22 and AN23 adjacent to the AN21. As a result of the antenna switching, when the communication quality is lowered, the macro diversity communication is resumed by returning to the original antenna combination, and the antenna switching is performed with a different antenna combination in the next period T.

[Macro diversity communication sequence]
FIG. 11 is an example of a sequence in the case of realizing macro diversity communication with a terminal.

  In the example of FIG. 11, the wireless terminal device MS11, the wireless units R11 to 1n, the received power measuring unit 104, the signal processing units 1031 to 103m, and the signal distribution in the wireless unit control device G1 that collectively controls the wireless units R11 to 1n. Operation of the unit 102, the antenna selection unit 111, the history information management unit 106, and the antenna information creation unit 109 is shown.

  The radio unit controller G1 uses the received power measurement unit 104 to measure the received power of the uplink signal from the radio terminal device MS11 for each antenna of each radio unit using the received power measurement timing as a trigger (S101). The reception power measurement unit 104 notifies the reception power measurement result to the antenna selection unit 111 of the radio unit controller G1 as a reception power notification (S102). The antenna selection unit 111 aggregates the received power notification and stores it in the received power aggregation information storage unit 105, and determines whether or not macro diversity is possible (S103).

  As a result of this determination, if it is determined that macro diversity is possible, antenna combination information stored in the antenna combination information storage unit 110 is acquired from the antenna information creation unit 109 (S104), and the antenna used for macro diversity is acquired. Is selected (S105). The antenna selection unit 111 sends a signal distribution change instruction (S106) to the signal distribution unit 102 based on the selected antenna combination information. Based on the parameter information of the signal distribution change instruction, the signal distribution unit 102 distributes the downlink data to the wireless terminal device MS11 to the appropriate signal processing unit 103 and starts transmission. In addition, the antenna selection unit 111 sends a use antenna change instruction (S107) to the plurality of signal processing units 103 that control the radio unit to which the antenna selected as the macro diversity use antenna belongs. Based on the parameter information of the used antenna change instruction, the signal processing unit 103 controls the downlink signal transmission power related to the antenna of the corresponding radio unit and starts macro diversity communication (S108).

  After the macro diversity communication is started, the antenna selection unit 111 sends a macro diversity start notification (S109) using the used antenna combination information as a parameter to the history information management unit 106. The history information management unit 106 acquires signal quality information such as received power from the received power measurement unit 104 in response to the macro diversity start notification (S110), and stores it in the macro diversity history information storage unit 107 in association with the antenna combination. The history information update notification (S111) is sent to the antenna information creation unit 109. The antenna information creation unit 109 creates antenna combination information only when history information is updated based on the antenna information update timer. If the history information update notification has not been received when the antenna information update timer has timed out (S112), the antenna combination information is not updated, and the state again waits for the timeout. When the history information update notification is received when the antenna information update timer times out (S113), the history information stored in the macro diversity history information storage unit 107 is acquired from the history information management unit 106 (S114), and the antenna combination information is acquired. The antenna combination information in the storage unit 110 is updated (S115).

  Note that the start sequence of macro diversity communication is not limited to the above sequence.

[Antenna switching sequence]
FIG. 12 is an example of an antenna switching sequence during execution of macro diversity communication.

  During macro diversity communication (S201), when the antenna switching timer times out (S202), the antenna selection unit 111 performs antenna switching for an antenna adjacent to the currently used antenna (S203), and selects the selected antenna. Based on the combination information, a signal distribution change instruction (S204) is sent to the signal distribution unit 102, and a use antenna change instruction (S205) is sent to the signal processing unit 103. The signal processing unit 103 starts macro diversity communication with the switched antenna based on the parameter information of the used antenna change instruction (S206). After the macro diversity communication is started, the antenna selection unit 111 sends a macro diversity start notification (S207) using the used antenna combination information as a parameter to the history information management unit 106, and stores the macro diversity history information in the same manner as S109 and after in FIG. The history information / antenna combination information storage unit 109 updates the antenna combination information of the unit 107 (S208).

  After performing macro diversity communication by antenna switching for a certain period, evaluation of macro diversity communication by antenna switching is performed with an evaluation timer timeout after switching (S209) as a trigger. When the communication quality after the antenna switching is higher than that before the switching (S210), the macro diversity using the antenna used after the switching is continued. On the other hand, when the communication quality after the antenna switching is lower than before the switching (S211), a signal distribution change instruction is given to the signal distribution unit 102 based on the antenna combination information before the switching (S212), and the signal processing unit 103 is notified. In response to this, an antenna change instruction (S213) is sent, and macro diversity is resumed with the antenna before switching (S214). Also, when macro diversity using the antenna before switching is resumed, a macro diversity start notification (S215) using the antenna combination information used as a parameter is sent to the history information management unit 106 as in the switching, and the macro diversity history information storage is performed. The history information / antenna combination information storage unit 109 updates the antenna combination information of the unit 107 (S216).

  As described above, in this embodiment, the past results of macro diversity and the antenna combination at that time are held as history information, and the macro combination is performed by selecting the antenna combination with the highest communication quality. When deciding which antenna to use for macro diversity, it is possible to determine the combination of antennas in advance based on the history information of macro diversity performed in the past, so that fluctuations in the instantaneous value of received power and measurement errors may occur. An efficient antenna combination can be selected. In addition, by using history information, it is possible to determine the antenna combination to be used based on radio wave adjacency rather than geographical adjacency, and consider the influence on radio wave conditions due to shielding and height differences. Thus, it is possible to perform macro diversity communication by selecting an optimum antenna.

  Although several embodiments have been described, these embodiments are presented as examples and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the scope of the invention. These embodiments and modifications thereof are included in the scope and gist of the invention, and are included in the invention described in the claims and the equivalents thereof.

  BS1, BS2 ... wireless base station device, G1, G2 ... wireless unit control device, R11-R1n, R21-R2n ... wireless unit, MS11-MS1m, MS21-MS2m ... wireless terminal device, GW ... gateway device, NW ... IP network / Public communication network, AN11 to 1n, AN21 to AN2n ... Radio communication antennas 101,201 ... Wireless communication unit, 102 ... Signal distribution unit, 103 ... Signal processing unit, 104 ... Reception power measurement unit, 105 ... Reception power aggregation Information storage unit 106 ... History information management unit 107 107 Macro diversity history information storage unit 108 Handover history unit information storage unit 109 Antenna information creation unit 110 Antenna combination information storage unit 111 Antenna selection unit

Claims (7)

A plurality of radio units including a plurality of antennas, and a plurality of radio units that perform radio communication with radio terminals by the antennas;
Measuring means for measuring the reception power of the uplink signal from the wireless terminal for each antenna;
Creating means for creating information representing a combination of antennas used for macro diversity communication by the plurality of wireless units with the wireless terminal;
Selection means for selecting a combination of antennas to be used for the wireless communication based on a measurement result of the received power and information representing a combination of the antennas;
Signal processing means for performing radio control of the plurality of radio units according to a combination of antennas selected by the selection means;
Accumulating means for accumulating macro diversity history information in which the signal quality of the macro diversity communication and the combination of the antennas are associated with each other;
The creation unit updates information representing a combination of the antennas based on the macro diversity history information.   When the macro diversity communication is being performed, the selection unit periodically performs the macro diversity communication in which the antenna used is changed, and when it is determined that the communication quality is higher than the combination of the antennas being performed, the combination of the antennas is selected. The radio base station apparatus according to claim 1, wherein the macro diversity communication is continued after being changed.   The radio base station apparatus according to claim 1, wherein the uplink signal is omni-transmitted from the radio terminal. The storage means further stores handover history information associating a radio unit connected before handover with a radio unit connected after handover at the time of performing handover in the radio terminal,
2. The radio base according to claim 1, wherein the creating unit creates information representing the combination of antennas based on the handover history information by determining that a combination of radio units connected before and after handover is adjacent. Station equipment.   The radio base station apparatus according to claim 1, wherein the signal quality includes at least one of reception power, throughput, and bit error rate in the macro diversity communication. A radio unit control apparatus comprising a plurality of antennas and controlling a plurality of radio units that perform radio communication with a radio terminal by the antennas,
Measuring means for measuring the reception power of the uplink signal from the wireless terminal for each antenna;
Creating means for creating information representing a combination of antennas used for macro diversity communication by the plurality of wireless units with the wireless terminal;
Selection means for selecting a combination of antennas to be used for the wireless communication based on a measurement result of the received power and information representing a combination of the antennas;
Signal processing means for performing radio control of the plurality of radio units according to a combination of antennas selected by the selection means;
Accumulating means for accumulating macro diversity history information in which the signal quality of the macro diversity communication and the combination of the antennas are associated with each other;
The radio unit controller according to claim 1, wherein the creating unit updates information representing a combination of the antennas based on the macro diversity history information. A wireless communication method used for a wireless unit control apparatus that includes a plurality of antennas and controls a plurality of wireless units that perform wireless communication with a wireless terminal using the antennas,
Measuring the received power of the uplink signal from the wireless terminal for each antenna;
Creating information representing a combination of antennas used for macro diversity communication by the plurality of wireless units with the wireless terminal;
Selecting a combination of antennas used for the wireless communication based on a measurement result of the received power and information representing a combination of the antennas;
Performing radio control of the plurality of radio units according to the combination of the selected antennas;
Storing macro diversity history information in which the signal quality of the macro diversity communication and the combination of the antennas are associated with each other, and
In the creating, a wireless communication method, wherein information representing a combination of the antennas is updated based on the macro diversity history information.

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