JP5767038B2 - Wireless communication system, base station control apparatus, and base station control method - Google Patents

Description

  The present invention relates to a radio communication system, a base station control device, and a base station control method.

In a wireless communication system, a terminal device located between cells and between sectors has a wireless communication quality, for example, a CINR (Carrier to Interference Noise Ratio) due to interference from a plurality of base station devices and interference from a plurality of sectors. As a result, there is a problem that high user throughput cannot be obtained.
On the other hand, a technique for improving the radio communication quality of terminal devices located between cells by performing MIMO (Multiple Input Multiple Output) transmission using a plurality of antennas possessed by different base station devices. (For example, Patent Document 1). Such a technique is called multi-base station cooperation.

By the way, although multiple base station cooperation can improve the radio | wireless communication quality of the terminal device located between cells, since several base station apparatuses allocate a radio | wireless resource with respect to one terminal device, one Compared with the case where the base station apparatus allocates radio resources to one terminal apparatus, the radio capacity of the radio communication system is reduced and the throughput of the entire radio communication system is reduced.
In particular, when there are many terminal devices in the vicinity of a base station device, the terminal device is in a state in which high throughput can be provided to the terminal device. As a result, a large number of radio resources are allocated to the terminal device, and the opportunity to allocate radio resources to terminal devices existing in the vicinity of the base station apparatus may be reduced. In this case, the throughput of the wireless communication system is reduced.
In view of this, studies have been made to maintain the throughput of the entire wireless communication system while improving the throughput of the terminal device to which the cooperation of a plurality of base stations is applied by the scheduler which is an upper layer.

JP 2009-2119010 A

  However, if each base station apparatus is controlled in an upper layer, the control becomes complicated, and an expensive control apparatus is required. Further, when the number of terminal devices connected to each base station device increases, the control becomes more complicated, the processing speed in the control device decreases, and the scheduler allocates radio resources according to the position of each terminal device. However, a sufficient solution has not been achieved in that the radio resources allocated to the terminal devices located in the vicinity of the base station device are insufficient.

  The present invention has been made to solve the above problems, and an object of the present invention is to provide a radio communication system, a base station control device, and a base station control method that improve throughput when a plurality of base stations cooperate. is there.

  In order to solve the above problem, the present invention is a wireless communication system including a base station control device that controls cooperation between a plurality of base stations that simultaneously communicate with a plurality of base station devices and a terminal device, The cell of the base station apparatus is divided into a neighboring sector that is an area in the vicinity of the base station apparatus and a boundary sector that is an area other than the neighboring sector, and the base station control apparatus includes: Based on the number of radio resources that can be allocated to the terminal device, the determination result of the cooperation control determination unit that determines whether or not to perform cooperation between a plurality of base stations in the boundary sector of the base station device, and the determination result of the cooperation control determination unit In response, a base station control unit that causes a plurality of base stations to cooperate in the boundary sector of the base station apparatus and that allocates radio resources for each of the neighboring sectors and the boundary sectors. Is a wireless communication system, characterized in that e.

Further, the present invention is the above-described invention, wherein the base station device includes a first wireless communication unit communicating with a terminal device located in the neighboring sector, and an antenna connected to the first wireless communication unit. And a second wireless communication unit that is connected to an antenna having a large tilt angle and communicates with a terminal device located in the boundary sector.
Further, the present invention is the above-described invention, wherein the base station device has a first wireless communication unit that communicates with a terminal device located in the neighboring sector, and transmission power is larger than that of the first wireless communication unit, And a second wireless communication unit communicating with a terminal device located in the boundary sector.
Further, the present invention is the above-described invention, wherein the base station control device further sets the first radio communication unit for each base station device based on the number of radio resources that can be allocated to the terminal device. A sector division determination unit that determines whether or not to operate, wherein the base station control unit determines that the sector division determination unit does not operate the first radio communication unit; On the other hand, wireless communication is performed with a terminal device located in the neighboring sector.

  Further, the present invention performs a plurality of base station cooperation in which a plurality of base station apparatuses and one terminal apparatus communicate simultaneously, and a cell of the base station apparatus includes a neighboring sector that is an area near the base station apparatus, A base station controller in a radio communication system that is divided into border sectors that are areas other than the neighboring sectors, the base station apparatus based on the number of radio resources that can be allocated to the terminal apparatus A cooperation control determination unit that determines whether or not to perform cooperation between a plurality of base stations in the boundary sector of the station device, and a plurality of base station cooperation in the boundary sector of the base station device according to a determination result of the cooperation control determination unit And a base station control unit that assigns radio resources to each of the neighboring sectors and the boundary sectors.

  Further, the present invention performs a plurality of base station cooperation in which a plurality of base station apparatuses and one terminal apparatus communicate simultaneously, and a cell of the base station apparatus includes a neighboring sector that is an area near the base station apparatus, , A base station control method in a radio communication system divided into boundary sectors that are areas other than the neighboring sectors, the base station apparatus based on the number of radio resources that can be allocated to a terminal apparatus A cooperation control determination step for determining whether or not to perform cooperation between a plurality of base stations in the boundary sector of the station apparatus, and a plurality of base station cooperation in the boundary sector of the base station apparatus, according to a determination result in the cooperation control determination step And a base station control step for allocating radio resources for each of the neighboring sectors and the boundary sectors. A base station control method.

  According to the present invention, the cell of the base station apparatus is divided into a neighboring sector and a boundary sector, it is determined whether or not multiple base station cooperation is performed with respect to a terminal apparatus located in the boundary sector, and a plurality of cells are determined according to the determination result. The base station cooperation was done. As a result, even when multiple base station cooperation is performed, it is possible to suppress a decrease in the number of radio resources to be allocated to terminal devices located in the vicinity of the base station device, and to maintain an opportunity to allocate radio resources to the terminal device. . In addition, for terminal devices located in the boundary sector, the throughput can be improved by cooperating with a plurality of base stations, so that the throughput in the radio communication system can be improved.

It is a schematic block diagram which shows the structure of the radio | wireless communications system 100 in this embodiment. It is the schematic which shows the example of how to divide the radio zone in the 1st radio | wireless communication part 11 and the 2nd radio | wireless communication part 12 in this embodiment. It is a flowchart which shows the determination process of multiple base station cooperation by the base station control apparatus 2 in this embodiment. FIG. 2 is a schematic diagram illustrating an operation example of a wireless communication system 100 in the present embodiment. It is the 1st schematic diagram showing the example to which radio communications system 100 in this embodiment is applied. It is the 2nd schematic diagram which shows the Example which applied the radio | wireless communications system 100 in this embodiment. It is the schematic which shows the Example which divides | segments a cell into the vicinity sector and boundary sector in this embodiment. It is the schematic which shows the operation | movement of the modification of this embodiment.

  Hereinafter, a radio communication system, a base station control device, and a base station control method according to embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 is a schematic block diagram illustrating a configuration of a wireless communication system 100 according to the present embodiment. As shown in the figure, the radio communication system 100 includes a plurality of base station apparatuses 1, a base station control apparatus 2, and at least one terminal apparatus 3.

The base station apparatus 1 includes a first radio communication unit 11, at least one second radio communication unit 12, and a communication control unit 13.
The 1st radio | wireless communication part 11 performs radio | wireless communication with the terminal device 3 located in the vicinity sector which is a radio | wireless zone of the vicinity of an own apparatus. Here, the wireless zone in the vicinity of the base station device 1 is a wireless communication quality of a signal received from the base station device 1 is a predetermined threshold value compared to the wireless communication quality of a signal received from another base station device 1. This is an area with the above difference, and it is an area in which an increase in throughput cannot be expected even when a plurality of base station cooperation is applied to the terminal device 3 located in the area.

  The 2nd radio | wireless communication part 12 performs radio | wireless communication with the terminal device 3 located in the boundary sector which is a radio zone other than a nearby sector among the cells of an own apparatus. When the base station apparatus 1 includes a plurality of second radio communication units 12, the boundary sectors of the second radio communication units 12 are different radio zones. The second wireless communication unit 12 performs wireless communication with the terminal device 3 in the same frequency band as the first wireless communication unit 11. Further, the division of cells by the first wireless communication unit 11 and the second wireless communication unit 12 is performed using a known technique (for example, the technique described in Japanese Patent Application Laid-Open No. 2008-219338).

  The communication control unit 13 causes the second wireless communication unit 12 to perform multiple base station cooperation in accordance with a control signal received from the base station control device 2. In addition, the communication control unit 13 transmits information indicating the reception status received from the terminal device 3 by the first radio communication unit 11 and the second radio communication unit 12 to the base station control device 2. Here, the information indicating the reception status includes, for example, information indicating the number of signals effective for cooperation with a plurality of base stations among signals received by the terminal device 3 from the base station device 1. A signal effective for cooperation with a plurality of base stations is a signal having a wireless communication quality equal to or higher than a predetermined wireless communication quality (for example, CINR). The base station device 1 is identified based on PN (Pseudo Noise) assigned in advance to each of the first radio communication unit 11 and the second radio communication unit 12. Each PN has a different value, and the first wireless communication unit 11 and the second wireless communication unit 12 can be identified using the PN.

The base station control device 2 controls whether or not to perform multiple base station cooperation in each base station device 1. In addition, the base station control device 2 includes a cooperation target storage unit 21, a cooperation determination unit 22, and a base station control unit 23.
The cooperation target storage unit 21 stores, for each boundary sector of the base station device 1, cooperation target information in which the boundary sector is associated with a boundary sector that performs base station cooperation. In this cooperation target information, the boundary sector is represented using an identifier for identifying the base station device 1 and an identifier for identifying the sector of the base station device 1. The neighboring sector is not included in the cooperation target information. This is because the first wireless communication unit 11 can improve the throughput by allocating a plurality of radio resources without performing the cooperation of a plurality of base stations with respect to the terminal device 3 located in the neighboring sector.

Based on the number of radio resources that can be allocated to the terminal device 3 in the boundary sector of the base station device 1 and the cooperation target information stored in the cooperation target storage unit 21, the cooperation determination unit 22 It is determined whether or not to cooperate with a plurality of base stations in the boundary sector.
The base station control unit 23 instructs the base station device 1 to perform cooperation between a plurality of base stations in the boundary sector of the base station device 1 according to the determination result of the cooperation determination unit 22, and the first wireless communication unit 11 provided in the base station device 1. And the second radio communication unit 12 transmits a control signal including an instruction to allocate radio resources to the terminal device 3 to the base station device 1.

FIG. 2 is a schematic diagram illustrating an example of how to divide radio zones (cells) in the first radio communication unit 11 and the second radio communication unit 12 in the present embodiment. As shown in the figure, the tilt angle θ1 of the antenna connected to the first wireless communication unit 11 is made larger than the tilt angle θ2 of the antenna connected to the second wireless communication unit 12. Here, as shown in FIG. 2, the tilt angle is an angle formed by the radiation direction (beam) of the antenna with respect to the horizontal direction.
Accordingly, the first wireless communication unit 11 performs wireless communication with the terminal device 3 located in the neighboring sector of the own device, and the second wireless communication unit 12 is located in the boundary sector formed outside the neighboring sector. Wireless communication.

  As described above, the first wireless communication unit 11 and the second wireless communication unit 12 perform space division multiplexing that divides a wireless zone to be communicated. Thereby, the 1st radio | wireless communication part 11 and the 2nd radio | wireless communication part 12 can perform radio | wireless communication with the terminal device 3 mutually independently using the same frequency band.

  FIG. 3 is a flowchart showing determination processing for cooperation with a plurality of base stations by the base station control device 2 in the present embodiment. The cooperation determination unit 22 performs the processes of steps S101 to S106 illustrated in FIG. 3 for each terminal device 3 that is performing wireless communication with the second wireless communication unit 12 of the base station device 1 in the wireless communication system 100. In other words, the determination process is performed for each terminal apparatus 3 that is located in the boundary sector and is performing wireless communication with the base station apparatus 1.

First, based on the information received via each base station device 1, the cooperation determination unit 22 uses the terminal device 3 from the plurality of base station devices 1 to perform two or more PN (Pseudo Noise) effective for cooperation with the plurality of base stations. It is determined whether or not (pseudo noise) is received (step S101).
When two or more PNs are not received by the terminal device 3 (step S101: NO), the cooperation determination unit 22 proceeds with the process to step S106, and when two or more PNs are received (step S101: YES), it is determined whether or not the number of radio resources that can be allocated by the second radio communication unit 12 with which the terminal device 3 performs radio communication is greater than a predetermined threshold P (step S102).

When the number of radio resources that can be allocated by the second radio communication unit 12 with which the terminal device 3 performs radio communication is equal to or less than the threshold value P (step S102: NO), the cooperation determination unit 22 advances the process to step S106.
On the other hand, when the number of assignable wireless resources is greater than the threshold value P (step S102: YES), the cooperation determination unit 22 determines that the terminal device 3 is wireless based on the cooperation target information stored in the cooperation target storage unit 21. It is determined whether there is a boundary sector corresponding to the second wireless communication unit 12 performing communication and a boundary sector that is a candidate for cooperation with a plurality of base stations (step S103).

When there is no boundary sector that is a candidate for cooperation with a plurality of base stations (step S103: NO), the cooperation determination unit 22 advances the process to step S106.
On the other hand, when there is a boundary sector that is a candidate for cooperation with a plurality of base stations (step S103: YES), the cooperation determination unit 22 determines the radio resources that can be allocated by the second wireless communication unit 12 corresponding to the candidate boundary sector. It is determined whether or not the number is greater than a predetermined threshold value Q (step S104).

When the number of radio resources is larger than the threshold value Q (step S104: YES), the cooperation determination unit 22 sends a control signal indicating that wireless communication is performed to the terminal device 3 using the multiple base station cooperation. (Step S105), and the determination process ends.
On the other hand, when the number of radio resources is equal to or less than the threshold value Q (step S104: NO), the cooperation determination unit 22 transmits a control signal indicating that wireless communication is performed without using multiple base station cooperation to the terminal device 3. It transmits with respect to the station apparatus 1 (step S106), and a determination process is complete | finished.
The threshold value P and the threshold value Q are determined in advance based on simulations and actual measurement results.

The base station control device 2 performs the above-described determination process, determines whether to perform wireless communication with the base station device 1 using the cooperation of a plurality of base stations for each terminal device 3, and performs wireless communication with the terminal device 3. The second radio communication unit 12 of the base station apparatus 1 that is performing the control is controlled. At this time, the cooperation determination unit 22 performs cooperation between multiple base stations when there is a margin in radio resources allocated to the terminal device 3 in the boundary sector (when there are more radio resources than the thresholds P and Q). By performing cooperation with a plurality of base stations, it is possible to prevent a shortage of radio resources and a decrease in the throughput of the terminal device 3. Further, in the radio communication system 100, the second radio communication unit 12 and the first radio communication unit 11 that perform cooperation with a plurality of base stations can allocate radio resources independently of each other.
As described above, the radio communication system 100 determines whether the base station control apparatus 2 applies the cooperation of the plurality of base stations by simple control of comparing the number of radio resources, and the terminal apparatus 3 located in the neighboring sector. The overall throughput can be improved by improving the throughput of the terminal device 3 to which the cooperation of the plurality of base stations can be applied without affecting the network.

In addition, the wireless communication system 100 is located in the vicinity of the base station apparatus 1 by providing a nearby sector to which the base station cooperation is not applied in the vicinity of each base station apparatus 1. The terminal device 3 that receives a signal having a certain radio communication quality or higher is controlled so as not to apply the multiple base station cooperation.
FIG. 4 is a schematic diagram illustrating an operation example of the wireless communication system 100 in the present embodiment. For example, as shown in FIG. 4 (a), when there is a terminal device 3 that is located in the vicinity of the base station device 1a and receives signals of a certain radio communication quality or higher from the base station device 1a and the base station device 1b, In the terminal device 3, there is a large difference between the wireless communication quality of the signal received from the base station device 1a and the wireless communication quality of the signal received from the base station device 1b. I cannot expect improvement. Rather, there is a high possibility that radio resources due to the application of multiple base station cooperation are wasted. In addition, when there is no criterion for determining whether or not to apply base station cooperation, in the state shown in FIG. 4A, radio resource may be wasted because multiple base station cooperation is always applied.
On the other hand, in the wireless communication system 100, as shown in FIG. 4B, a neighboring sector to which the multiple base station cooperation is not applied is provided. Thereby, even when the terminal device 3a receives a signal of a certain radio communication quality or higher from the base station device 1a and the base station device 2b, the application of the cooperation of multiple base stations to the terminal device 3 located in the neighboring sector Do not do. As a result, it is possible to prevent radio resources from being allocated unnecessarily by applying the cooperation of a plurality of base stations to the terminal device 3 located in the boundary sector where improvement in throughput can be expected, and to improve the throughput. Can do.

FIG. 5 is a schematic diagram illustrating an example in which the wireless communication system 100 according to the present embodiment is applied. In the present embodiment, a case where the wireless communication system 100 includes two base station apparatuses 1a and 1b and each base station apparatus 1a and 2b includes one second wireless communication unit 12 is illustrated.
As shown in the figure, the cell of each base station apparatus 1a, 2b is divided into a neighboring sector (sector 2) near the base station apparatuses 1a, 1b and a boundary sector (sector 1). In addition, there is an overlapping area A in the boundary sector (sector 1) of the base station apparatuses 1a and 1b. In this area A, wireless communication using cooperation between a plurality of base stations can be performed with respect to the terminal apparatus 3, and the sector 1 of the base station apparatus 1a and the sector 1 of the base station apparatus 1b are boundaries that perform the cooperation of a plurality of base stations. It is stored in advance in the cooperation target storage unit 21 in association with the sector.

  The base station control device 2 provides a plurality of base stations to the terminal device 3b receiving PNs corresponding to the boundary sector (sector 1) of the base station device 1a and the boundary sector (sector 1) of the base station device 1b. It is determined whether or not the station cooperation is applied, and the determination result is transmitted to the base station apparatuses 1a and 1b. When multiple base station cooperation is applied to the terminal device 3b, the terminal device 3a located in the sector near the base station device 1a performs radio communication with the base station device 1a, and the terminal device 3b located in the boundary sector area A. Performs wireless communication with the base station apparatus 1a and the base station apparatus 1b using a plurality of base station cooperations.

  At this time, the terminal device 3a and the terminal device 3b perform wireless communication with the base station device 1a, but radio resources are physically separated in the neighboring sector (sector 2) and the boundary sector (sector 1). Radio resources are allocated independently. As a result, even if wireless communication using cooperation between a plurality of base stations is performed for the terminal device 3b, the throughput in the wireless communication system 100 can be improved without decreasing the opportunity to allocate wireless resources to the terminal device 3a. .

FIG. 6 is a schematic diagram illustrating an example to which the wireless communication system 100 according to the present embodiment is applied. Here, a case where the wireless communication system 100 includes two base station apparatuses 1a and 1b, and each base station apparatus 1a and 1b includes three second wireless communication units 12 is illustrated.
As shown in the figure, the cell of each base station apparatus 1a, 1b is divided into a neighboring sector (sector 4) and three boundary sectors (sectors 1 to 3). At this time, the three second wireless communication units 12 use different wireless sectors (sectors 1, 2, and 3) as communication target areas. Further, sector 2 and sector 3 of base station apparatus 1a and sector 1 of base station apparatus 1b have overlapping area B and area C, as shown in FIG. In this area B and area C, wireless communication using cooperation between a plurality of base stations can be performed to the terminal apparatus 3, and the sector 2 of the base station apparatus 1a and the sector 1 of the base station apparatus 1b cooperate with each other. Are stored in advance in the cooperation target storage unit 21 in association with the boundary sector. Similarly, the sector 3 of the base station apparatus 1a and the sector 1 of the base station apparatus 1b are associated with each other as a boundary sector that performs cooperation between a plurality of base stations and stored in advance in the cooperation target storage unit 21.

Whether or not the base station control device 2 applies the multiple base station cooperation to the terminal device 3b receiving the PN corresponding to the sector 3 of the base station device 1a and the sector 1 of the base station device 1b. And the determination result is transmitted to the base station apparatuses 1a and 1b. When multiple base station cooperation is applied to the terminal device 3b, the terminal device 3a located in the sector near the base station device 1a performs radio communication with the base station device 1a, and the terminal device 3b located in the boundary sector area A. Performs wireless communication with the base station apparatus 1a and the base station apparatus 1b using a plurality of base station cooperations.
The wireless communication system 100 performs wireless communication for the terminal device 3b using the cooperation of a plurality of base stations without affecting the allocation of wireless resources to the terminal device 3a located in the neighboring sector of the base station device 1a. By causing 1b to perform, the throughput can be improved.

  FIG. 7 is a schematic diagram showing an example in which cells are divided into neighboring sectors and boundary sectors in the present embodiment. In the figure, (a) when applied to an omni-cell base station device, (b) when applied to a base station device with a two-sector configuration, (c) when applied to a base station device with a three-sector configuration, and ( d) When applied to a base station apparatus having a 6-sector configuration, examples of forming neighboring sectors and boundary sectors are shown. As shown in the figure, when the present invention is applied to an existing base station apparatus, it is applied by adding a first wireless communication unit 11 that communicates with a terminal apparatus 3 located in a neighboring sector to the base station apparatus. can do.

In addition, in the base station device 1, when there is a surplus of radio resources, radio communication is performed with the terminal device 3 using the second radio communication unit 12 without using the first radio communication unit 11, and radio resources are insufficient. In addition, wireless communication with the terminal device 3 may be performed using the first wireless communication unit 11 and the second wireless communication unit 12. In this case, an antenna or the like is set in the second radio communication unit 12 so as to cover the boundary sector and the neighboring sector as a radio zone, and the base station control device 2 connects to the terminal device 3 for each base station device 1. You may make it provide the sector division | segmentation determination part which determines whether the 1st radio | wireless communication part 11 of each base station apparatus 1 is operated based on the number of the radio | wireless resources which can be allocated.
Thereby, when there is a margin in radio resources, the first radio communication unit 11 can be stopped, and power consumption in the base station apparatus 1 can be reduced. At this time, the neighboring sector that is the wireless zone of the first wireless communication unit 11 is treated as a sector that does not cooperate with the plurality of base stations, and therefore, the plurality of base stations regardless of whether or not the first wireless communication unit 11 operates. There is no need to change the combination of sectors to be linked. That is, since it is not necessary to update the cooperation target information stored in the cooperation target storage unit 21 of the base station control device 2, the operation / stop of the first wireless communication unit 11 can be quickly switched.

  Further, in the above-described embodiment, the configuration in which wireless communication with the terminal device 3 is performed using the cooperation of a plurality of base stations between the boundary sectors of different base station devices 1, but different boundaries of the same base station device 1 are described. You may make it perform radio | wireless communication with the terminal device 3 using multiple base station cooperation between sectors. In this case, the cooperation target storage unit 21 may store in advance cooperation target information in which adjacent boundary sectors of the same base station device 1 are associated. A different PN may be assigned to each boundary sector.

  FIG. 8 is a schematic diagram showing the operation of a modification of the present embodiment. In this modification, the base station apparatus 1 includes a first wireless communication unit 11 that forms a sector 4 and three second wireless communication units 12 that form sectors 1 to 3. . The sector division determination unit in the base station control device 2 determines that the first wireless communication unit 11 is activated when the number of radio resources allocated to the terminal device 3 in the base station device 1 is equal to or less than a predetermined threshold. The base station apparatus 1 increases the number of sectors 4 to which radio resources can be allocated independently. As a result, even when wireless communication is performed using a plurality of base station linkages for the terminal device 3b located near the boundary between the sector 1 and the sector 2, the terminal device 3b is located in the neighborhood sector (sector 4) of the base station device 1. It is possible to perform wireless communication with the terminal device 3a without reducing the wireless resources allocated to the terminal device 3a. As a result, the throughput of the wireless communication system can be improved by increasing the throughput of the terminal device 3b. At this time, the sector division determination unit may further notify the terminal device 3 located in the neighboring sector of the sector change via the base station device 1.

  Further, in the above-described embodiment, the configuration in which the wireless zones in the first wireless communication unit 11 and the second wireless communication unit 12 are divided into neighboring sectors and boundary sectors according to the tilt angles of the respective antennas has been described. The configuration is not limited to this. For example, the gains of the reception and transmission amplifiers of the second wireless communication unit 12 are made larger than the gains of the reception and transmission amplifiers of the first wireless communication unit 11, and the wireless zone of the second wireless communication unit 12 is set. The first wireless communication unit 11 may be wider than the wireless zone, and a neighboring sector and a boundary sector may be provided. In this case, when the terminal device 3 located in the neighboring sector receives the signals transmitted from the first wireless communication unit 11 and the second wireless communication unit 12, the terminal device 3 detects the signal of the first wireless communication unit 11 using the PN. Then, wireless communication with the first wireless communication unit 11 may be performed. That is, the cell of the radio base station apparatus 1 may be divided into a neighboring sector and a boundary sector by using transmission power control and code division multiplexing.

Further, in the determination process for cooperation with a plurality of base stations (FIG. 3), the case where there is one boundary sector that is a candidate for cooperation with a plurality of base stations has been described, but a plurality of boundary sectors may be used as candidates. In this case, it may be determined whether or not to cooperate with a plurality of base stations for each boundary sector, and cooperation with a plurality of base stations may be performed when radio resources that are equal to or greater than a threshold can be allocated in two or more boundary sectors.
In step S103 (FIG. 3), it is determined whether or not the boundary sector of the multiple base station cooperation candidate stored as the cooperation target information matches the boundary sector corresponding to the PN received by the terminal device 3. May also be performed. At this time, if they do not match, it may be handled as a case where no boundary sector exists.

  Note that a program for realizing the function of the base station control device 2 in the present invention is recorded on a computer-readable recording medium, and the program recorded on the recording medium is read into a computer system and executed. You may perform the determination process of base station cooperation. Here, the “computer system” includes an OS and hardware such as peripheral devices. The “computer system” includes a WWW system having a homepage providing environment (or display environment). The “computer-readable recording medium” refers to a storage device such as a flexible medium, a magneto-optical disk, a portable medium such as a ROM and a CD-ROM, and a hard disk incorporated in a computer system. Further, the “computer-readable recording medium” refers to a volatile memory (RAM) in a computer system that becomes a server or a client when a program is transmitted via a network such as the Internet or a communication line such as a telephone line. In addition, those holding programs for a certain period of time are also included.

  The program may be transmitted from a computer system storing the program in a storage device or the like to another computer system via a transmission medium or by a transmission wave in the transmission medium. Here, the “transmission medium” for transmitting the program refers to a medium having a function of transmitting information, such as a network (communication network) such as the Internet or a communication line (communication line) such as a telephone line. 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.

DESCRIPTION OF SYMBOLS 1, 1a, 1b ... Base station apparatus 2 ... Base station control apparatus 3, 3a, 3b ... Terminal device 11 ... 1st wireless communication part 12 ... 2nd wireless communication part 13 ... Communication control part 21 ... Cooperation object memory | storage part 22 ... Cooperation determination unit 23 ... base station control unit 100 ... wireless communication system

Claims (6)

A wireless communication system comprising a base station controller that controls cooperation between a plurality of base stations and a plurality of base station devices that simultaneously communicate with one terminal device,
The cell of the base station device is divided into a neighboring sector that is a region near the base station device and a boundary sector that is a region other than the neighboring sector,
The base station apparatus location is,
A first wireless communication unit communicating with a terminal device located in the neighboring sector;
A second wireless communication unit communicating with a terminal device located in the boundary sector;
With
The base station controller is
Based on the number of radio resources that the base station device can allocate to the terminal device, a cooperation control determination unit that determines whether or not to perform base station cooperation in the boundary sector of the base station device;
A base station control unit that causes a plurality of base stations to cooperate in the boundary sector of the base station apparatus and allocates radio resources for each of the neighboring sectors and the boundary sector according to a determination result of the cooperation control determination unit And
The first wireless communication unit and the second wireless communication unit are assigned pseudo noise having different values,
The cooperation control determination unit determines whether or not to perform multi-base station cooperation when the terminal device receives pseudo noise of two or more different second wireless communication units. Communications system. The wireless communication system according to claim 1, wherein a tilt angle of an antenna connected to the first wireless communication unit is larger than a tilt angle of an antenna connected to the second wireless communication unit. The wireless communication system according to claim 1, wherein the second wireless communication unit has a transmission power larger than that of the first wireless communication unit. The base station control device further includes:
A sector division determination unit that determines whether to operate the first radio communication unit based on the number of radio resources that can be allocated to the terminal device for each base station device,
The base station controller
The second wireless communication unit of the base station apparatus that has determined that the sector division determination unit does not operate the first wireless communication unit causes wireless communication with a terminal device located in the neighboring sector. The radio | wireless communications system as described in any one of Claims 1-3. A plurality of base station devices and a single terminal device communicate with each other at the same time, and a base station device cell includes a neighboring sector that is a region in the vicinity of the base station device, and other than the neighboring sectors. A base station controller in a wireless communication system divided into boundary sectors that are regions,
Based on the number of radio resources that the base station device can allocate to the terminal device, a cooperation control determination unit that determines whether or not to perform base station cooperation in the boundary sector of the base station device;
A base station control unit that causes a plurality of base stations to cooperate in the boundary sector of the base station apparatus and allocates radio resources for each of the neighboring sectors and the boundary sector according to a determination result of the cooperation control determination unit It equipped with a door,
The base station device includes a first wireless communication unit that communicates with a terminal device located in the neighboring sector, and a second wireless communication unit that communicates with a terminal device located in the boundary sector, the first wireless communication unit And the second wireless communication unit are assigned pseudo-noise having different values,
The cooperation control determination unit determines whether or not to perform multiple base station cooperation when the terminal device receives pseudo noise of the two or more different second wireless communication units.
A base station controller characterized by that. A plurality of base station devices and a single terminal device communicate with each other at the same time, and a base station device cell includes a neighboring sector that is a region in the vicinity of the base station device, and other than the neighboring sectors. A base station control method in a wireless communication system divided into boundary sectors that are regions,
A linkage control determination step for determining whether or not to perform a plurality of base station linkages in the boundary sector of the base station device, based on the number of radio resources that the base station device can allocate to the terminal device;
A base station control step for causing a plurality of base stations to cooperate in the boundary sector of the base station apparatus and allocating radio resources for each of the neighboring sectors and the boundary sectors according to the determination result in the cooperation control determination step. And
The base station device includes a first wireless communication unit that communicates with a terminal device located in the neighboring sector, and a second wireless communication unit that communicates with a terminal device located in the boundary sector, the first wireless communication unit And the second wireless communication unit are assigned pseudo-noise having different values,
In the cooperation control determination step, it is determined whether or not to perform multi-base station cooperation when the terminal device receives pseudo noise of two or more different second wireless communication units.
The base station control method comprising the this.

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