JP5150544B2 - Base station control apparatus and base station control method - Google Patents

Description

  The present invention relates to a base station control device and a base station control method.

  In recent years, in the mobile phone service in Japan, the third generation called IMT-2000 (International Mobile Telecommunications 2000) represented by W-CDMA (Wideband Code Division Multiple Access) and CDMA2000 (Code Division Multiple Access 2000). Mobile communication systems are becoming popular. Further, as the IMT-2000 advanced system and the IMT-2000 next-generation system, a standard for a fourth generation mobile communication system called IMT-Advanced is being formulated.

  IMT-Advanced aims to achieve a transmission rate of 1 Gbps when moving at low speed and a transmission rate of 100 Mbps when moving at high speed. In order to realize such high-speed communication, it is necessary to use a communication method using a wide frequency band. As one of such communication methods, orthogonal frequency division multiple access (Orthogonal Frequency Division) Multiple Access (OFDMA) system is known. The OFDMA scheme is a scheme in which a wide frequency band is divided into orthogonal narrow bands called subcarriers, and information is transmitted on each subcarrier. According to this OFDMA method, frequency characteristics generated in a radio apparatus are corrected for each subcarrier, or frequency multiplex transmission and frequency division multiple access are adaptively performed with respect to time variations of frequency characteristics generated in a transmission path. Therefore, it is attracting attention as one of the leading transmission methods for realizing broadband communication.

  In addition, the multiple input multiple output (MIMO) technique using a plurality of antennas receives signals individually transmitted from a plurality of antennas on the transmission side by the plurality of antennas on the reception side, and receives the received signals. As a technique for improving frequency utilization efficiency by separating spatial signals from the signal.

  In the cellular mobile communication system, a plurality of base stations are arranged, and a continuous communication service area is constructed by the communication area (cell) of each base station. When applying a communication method using, a guideline for allocating the entire frequency band to each cell is conceivable due to the limitation of the usable frequency region. In this case, for a mobile station located in the vicinity of the base station, the desired signal from the communication base station can be received at a high level, and the radio signal from the adjacent base station is lowered due to distance attenuation. As a result of broadband communication, high user throughput can be expected. However, for mobile stations located at cell boundaries, not only the level of the desired signal decreases due to distance attenuation, but also the radio signal of the adjacent base station becomes an interference signal at the same level as the communication signal, greatly degrading the communication quality. There is a problem that the effect of broadband communication cannot be obtained sufficiently. This problem becomes conspicuous especially in the downlink (line from the base station to the mobile station) because the transmission power of the base station is larger than that of the mobile station.

  For example, Patent Documents 1, 2, and 3 disclose countermeasures against the problem. In this conventional technology, a base station controller for controlling a plurality of base stations is provided, and the base station controller performs communication using a MIMO technology or the like in cooperation with a plurality of base stations to a mobile station at a cell boundary. Control multiple base stations.

JP 2007-134844 A JP 2007-043332 A International Publication No. 2006/016485 Pamphlet

Yukiji Yamauchi, “Toward Next-Generation High-Performance Communications”, Tokyo Denki University Press, 1995

  However, the above-described conventional technique has a problem of efficiently using radio resources of the entire cellular mobile communication system. When a plurality of base stations cooperate with a mobile station located at a cell boundary to perform communication using MIMO technology or the like, the mobile station occupies the radio resources of the plurality of base stations at that moment. As a whole cellular mobile communication system, the utilization efficiency of radio resources decreases.

  The present invention has been made in consideration of such circumstances, and its object is to improve the communication quality of each mobile station by communicating with one mobile station in cooperation with a plurality of base stations, and to achieve cellular communication. It is an object of the present invention to provide a base station control device and a base station control method capable of preventing a decrease in use efficiency of radio resources in the entire mobile communication system.

  In order to solve the above problems, a base station control apparatus according to the present invention includes a plurality of base stations, and a plurality of base stations are configured in a cellular mobile communication system in which a continuous communication service area is constructed by the communication area of each base station. A base station control apparatus for controlling the base station, the communication area is divided into a cooperation area that is a target of base station cooperative communication and a non-cooperation area that is not a target of base station cooperative communication, The base station control device comprises: a radio resource management means for managing radio resources separately in a radio resource area for non-cooperating areas and a radio resource area for cooperating areas in a radio resource area of each base station; Area discrimination means for determining whether the mobile station is in a non-cooperation area or a cooperation area, and radio resources to be allocated to mobile stations in the cooperation area The radio resource area for the non-cooperation area of the base station that communicates with the mobile station that is commonly reserved in the radio resource area for the cooperating area of each base station that performs cooperative communication and is allocated to the mobile station in the non-cooperation area And a radio resource allocating means secured in the above.

  In the base station control device according to the present invention, the radio resource allocating unit first secures radio resources for the base station cooperative communication in the radio resource area for the cooperative area, and then the surplus radio in the radio resource area for the cooperative area It is characterized by utilizing resources for non-base station cooperative communication.

  In the base station control apparatus according to the present invention, the radio resource management means is capable of changing the size of each area radio resource area.

  In the base station control apparatus according to the present invention, the radio resource management means dynamically sets the radio resource area for each area according to the degree of communication congestion in each area.

  In the base station control apparatus according to the present invention, the cooperation area is provided as an adjacent area between the cooperation target base stations for each combination of the cooperation target base stations, and a radio resource is prepared for each area. It is characterized by being.

  In the base station control apparatus according to the present invention, the area determining means determines the area to which the mobile station belongs based on information indicating radio reception quality from each base station in the mobile station, A mobile station that shows a combination of base stations different from a prescribed combination of base stations that perform cooperative communication in cooperation is handled as belonging to a non-cooperative area of the base station to which the mobile station is connected.

  In the base station control apparatus according to the present invention, the area determining means determines the area to which the mobile station belongs based on information indicating radio reception quality from each base station in the mobile station, For mobile stations that indicate a combination of base stations that is different from the standard combination of base stations that perform cooperative communication in a coordinated manner, the base stations included in the combination of the different base stations are selected from the ones with the best radio reception quality. A plurality of base stations are selected, and among the plurality of cooperation areas related to the selected base stations, the mobile station is treated as belonging to the cooperation area closer to the unselected base station with the worst wireless reception quality. And

  In the base station control apparatus according to the present invention, in the radio resource area of each base station, a radio for a virtual area corresponding to a combination of base stations different from a prescribed combination of base stations that performs base station cooperative communication in cooperation with each other In the radio resource area of each base station, the radio resource management means divides a radio resource into a radio resource area for a non-cooperation area, a radio resource area for a cooperation area, and a radio resource area for a virtual area. The area discriminating unit determines the area to which the mobile station belongs based on information indicating the radio reception quality from each base station in the mobile station, and performs base station cooperative communication in cooperation with each other. A mobile station indicating a combination of base stations different from the base station combination is treated as belonging to a virtual area, and the radio resource allocation means Relative movement station, commonly allocate radio resources for a virtual area of each base station included in the combination of said different base station, characterized in that.

  The base station control method according to the present invention is a base station control for controlling a plurality of base stations in a cellular mobile communication system in which a plurality of base stations are arranged and a continuous communication service area is constructed by the communication area of each base station. The communication area is divided into a cooperation area that is a target of base station cooperative communication and a non-cooperation area that is not a target of base station cooperative communication, and the radio resource area of each base station is It is divided into a radio resource area for the non-cooperative area and a radio resource area for the cooperating area, and a step of determining whether the mobile station is in the non-cooperative area or the cooperating area; A step of securing a radio resource to be allocated in common in a radio resource area for a cooperation area of each base station that performs base station cooperation communication with the mobile station, and a non-cooperation area The radio resource allocated to the mobile station, characterized in that it comprises the steps of securing a non-cooperative area for radio resource area of the base station communicating with the mobile station that.

  According to the present invention, a plurality of base stations cooperate with each other to communicate with one mobile station, thereby improving the communication quality of each mobile station and preventing a decrease in the efficiency of use of radio resources in the entire cellular mobile communication system. The effect that it can be obtained.

It is a schematic block diagram of the cellular mobile communication system which concerns on one Embodiment of this invention. It is an example of the cell structure which concerns on one Embodiment of this invention. It is a conceptual diagram which shows the structural example of the communication area (cell) which concerns on one Embodiment of this invention. It is an example of the cooperation area arrangement | positioning pattern corresponding to the area structure of FIG. It is a conceptual diagram of the logical resource table which concerns on one Embodiment of this invention. 5 is a flowchart of a base station control method according to an embodiment of the present invention. It is a conceptual diagram for demonstrating the radio | wireless resource allocation method which concerns on one Embodiment of this invention. It is a conceptual diagram of the logical resource table which concerns on other embodiment of this invention. It is a conceptual diagram which shows the structural example of the communication area (cell) which concerns on other embodiment of this invention.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a schematic configuration diagram of a cellular mobile communication system according to an embodiment of the present invention. In FIG. 1, a cellular mobile communication system includes a plurality of base stations 1 each providing a cell, a mobile station (user terminal) 2 that communicates by wireless connection to the base station 1, and a base that controls the plurality of base stations 1. It has a station controller 10. In FIG. 1, two base stations 1 (whose base station identifiers are A and B), a cell 3A provided by the base station 1 (A), and a cell 3B provided by the base station 1 (B) Illustrated.

  Each base station 1 is connected to the core network 5 via the backbone network 4. The backbone network 4 and the core network 5 each have a router 6. The base station controller 10 is provided in the backbone network 4 and is connected to each base station 1 by wire.

  In the cellular mobile communication system according to the present embodiment, the base station 1 and the user terminal 2 are provided with a plurality of antennas, and even when the base station 1 and the user terminal 2 communicate one-to-one, the plurality of base stations 1 cooperate. Even when communicating with the user terminal 2, transmission using MIMO technology (MIMO transmission) can be performed. Types of MIMO transmission (MIMO mode) include transmission diversity such as maximum ratio combining transmission diversity, space-time coding such as space-time coding, eigenbeam space multiplexing, and combinations thereof.

  In the cellular mobile communication system according to the present embodiment, the OFDMA method is used as the multiple access method between the base station 1 and the user terminal 2. In the present embodiment, it is assumed that the correspondence relationship (mapping method) between logical radio resources and physical radio resources is common to all base stations. When using OFDMA and MIMO transmission, a radio resource includes a time domain, a frequency domain, and a spatial domain. When performing MIMO transmission in which a plurality of base stations 1 cooperate with one user terminal 2, it is necessary to allocate the same radio resources to these base stations.

  The base station controller 10 acquires information on the base station 1 to be controlled and information on the user terminal 2 connected to the base station 1 from each base station 1. The base station controller 10 assigns the radio resources of all the base stations 1 to be controlled at once. The base station controller 10 transmits the radio resource allocation result to each base station 1.

  FIG. 2 is an example of a cell configuration according to this embodiment. In the example of FIG. 2, the cell is not divided into sectors, but the present invention is also applicable to the case where the cell is divided into sectors. In FIG. 2, each base station 1 (A to G) can communicate with the base station controller 10 by wire. Each base station 1 (A to G) provides cells 3A to 3G, respectively. The user terminal 2 can wirelessly connect to and communicate with the base station 1 of the cell in which it is located. A user terminal 2 located at an overlapping portion (cell boundary) of a plurality of cells can wirelessly connect to and communicate with the base stations 1 of the plurality of cells. Further, the user terminal 2 at the cell boundary can perform downlink communication by MIMO transmission in which a plurality of base stations 1 cooperate.

  Next, the base station control method according to this embodiment will be described. Hereinafter, for convenience of explanation, the base station 1 whose base station identifier is “A” is referred to as “base station A”, and the base station 1 whose base station identifier is “B” is referred to as “base station B”. In some cases, the reference “1” is omitted and “base station” and “base station identifier” are connected together.

In this embodiment, three base stations cooperate and perform base station cooperation communication.
FIG. 3 is a conceptual diagram illustrating a configuration example of a communication area (cell) according to the present embodiment. FIG. 3 shows a case where attention is paid to the base station A in the cell configuration of FIG. Each cell is divided into a cooperation area and a non-cooperation area. The cooperation area is an area that is a target of base station cooperation communication. The non-cooperation area is an area that is not a target of base station cooperation communication. In the example of FIG. 3, the cell 3A of the base station A is divided into one non-cooperation area (Area 0) and six cooperation areas (Area 1 to 6). Similarly, the cells 3B to 3G of the other base stations B to G are divided into one non-cooperation area (Area0) and six cooperation areas. A cooperation area identifier (Area 1-6) is given to the cooperation area for each combination of base stations (cooperation base stations) that perform base station cooperation communication. Therefore, the geographical position to which each cooperation area identifier is assigned is different for each base station.

  The cooperation area is provided as an adjacent area between the cooperation target base stations for each combination of the cooperation target base stations. It is assumed that base station cooperative communication is performed between three adjacent base stations in a common cooperative area (a cooperative area with the same identifier). In FIG. 3, for example, between base stations A, B, and C, it is assumed that base station cooperative communication is performed in a common cooperative area (Area 1). The reason why the cooperation areas are divided into a plurality of areas is to classify the cooperation areas without contradiction based on the cell arrangement of the cellular mobile communication system. Therefore, what is necessary is just to determine how many cooperation areas are divided according to cell arrangement.

  Which area (non-cooperation area (Area 0) or any one of the cooperation areas (Area 1 to 6)) the user terminal 2 is in is the location information of the user terminal 2 or each base in the user terminal 2 Judgment based on information indicating the radio reception quality from station 1 (Carrier to Interference and Noise power Ratio (CINR), Received Signal Strength Indicator (RSSI), etc.) Can do.

  FIG. 4 is an example of a cooperation area arrangement pattern corresponding to the area configuration of FIG. In FIG. 4, the numbers (1 to 6) written in the cells correspond to the numbers of the identifiers (Area 1 to 6) of the cooperation area, and indicate the cooperation areas (Area 1 to 6), respectively. In the example of FIG. 4, the arrangement of the cooperation areas in the cell is classified into three patterns α, β, and γ. Characters (α, β, γ) written in the cell indicate the cooperative area arrangement pattern α, β, γ of the cell. According to the cooperation area arrangement pattern of FIG. 4, radio resources can be allocated without contradiction by allocating radio resources according to the patterns α, β, and γ to each of the non-cooperation area and the cooperation area.

  FIG. 5 is a conceptual diagram of a logical resource table according to the present embodiment. The base station controller 10 has a logical resource table for each base station 1 to be controlled. The logical resource table is for holding a radio resource allocation result in one radio frame. In FIG. 5, the horizontal axis is the time axis and is in steps of OFDMA symbol units. The vertical axis is the frequency axis and is a unit of subcarrier. A radio resource amount corresponding to a rectangular area composed of a predetermined number of subcarriers n × a predetermined number of OFDMA symbols m is called a slot. The slot is defined such that an integer multiple of the number of OFDMA symbols m is the number of OFDMA symbols of one radio frame. The assignment of radio resources is performed on a slot basis.

  FIG. 5 shows an example of clustering of logical resource tables based on the area configuration of FIG. In FIG. 5, a logical subchannel is provided for each of one non-cooperation area (Area 0) and six cooperation areas (Area 1 to 6). A logical subchannel is a set of subcarriers assigned to the area. One logical subchannel is an integral multiple of the number n of subcarriers constituting the slot.

  When allocating radio resources to the user terminal 2 in the non-cooperation area (Area0), only radio resources of the base station 1 in the area need to be considered, and radio resources of other base stations 1 are considered. There is no need. On the other hand, when assigning radio resources to the user terminals 2 in the cooperation area (Area 1 to 6), in order to perform base station cooperation communication, assign the common radio resources of a plurality of base stations 1 to be linked. Consider.

  In the example of FIG. 5, the logical subchannel sizes of the areas 0 to 6 are equal, but the logical subchannel sizes may be different between areas. For example, the congestion degree of communication in each area is determined from the number of calls from the user terminal 2 in each area, the data communication amount, etc., and the logical subchannel size of the congested area is increased according to the congestion degree. On the other hand, the logical subchannels may be dynamically set so as to reduce the logical subchannel size in the non-congested area.

  FIG. 6 is a flowchart of the base station control method according to the present embodiment. Hereinafter, the base station control method according to the present embodiment will be described with reference to FIG.

  Step S1: The base station controller 10 determines the affiliation area of the user terminal 2 to which radio resources are allocated. Specifically, position information (such as GPS (Global Positioning System) measurement information of the user terminal 2) is received from the user terminal 2, and based on the position information, which area the user terminal 2 is in is determined. to decide. Alternatively, information (CINR, RSSI, etc.) indicating the radio reception quality from each base station 1 in the user terminal 2 is received from the user terminal 2, and in which area the user terminal 2 is located based on the radio reception quality information Determine whether.

  Step S2: The base station controller 10 allocates radio resources for the cooperation area to the user terminals 2 belonging to the cooperation area based on the result of Step S1. At this time, the base station controller 10 allocates the number of slots corresponding to the amount of radio resources necessary for the user terminal 2 in the logical resource table of each base station 1 that performs base station cooperative communication with the user terminal 2. Mapping is performed in the same radio resource area of the affiliation area. Thereby, the amount of radio resources necessary for the user terminal 2 that performs base station cooperative communication is commonly secured in the corresponding base stations 1.

  Step S3: The base station controller 10 determines whether or not to switch the radio resource allocation target area from the cooperation area to the non-cooperation area. As this switching determination method, for example, when there is no user terminal 2 belonging to the cooperation area, the radio resource allocation target area is switched from the cooperation area to the non-cooperation area. Alternatively, the radio resource allocation target area is switched from the cooperation area to the non-cooperation area at intervals. In this case, the switching timing for switching the radio resource allocation target area from the cooperation area to the non-cooperation area may be variable. For example, the communication amount of the user terminal 2 belonging to the cooperation area is compared with the communication amount of the user terminal 2 belonging to the non-cooperation area, and the period with the larger communication amount is lengthened according to the difference in the communication amount. Then, the switching timing is changed.

  As a result of step S3, when the radio resource allocation target area is switched from the cooperation area to the non-cooperation area, the process proceeds to step S4, and when not yet switched, the process returns to step S2.

  Step S4: The base station controller 10 allocates radio resources for the non-cooperation area to the user terminals 2 belonging to the non-cooperation area based on the result of step S1. At this time, the base station controller 10 uses the number of slots corresponding to the amount of radio resources necessary for the user terminal 2 in the radio resource area of the non-cooperative area in the logical resource table of the base station 1 that communicates with the user terminal 2. Map with. Thereby, the amount of radio resources necessary for the user terminal 2 is ensured in the corresponding base station 1.

  Step S5: The base station controller 10 refers to the logical resource table of each base station 1 to be controlled, and checks whether there are still radio resources for non-cooperative areas that can be allocated. As a result, when the radio resources for the non-cooperating area that can be allocated remain (step S5, NO), the process returns to step S4, and the base station 1 that has the radio resources for the non-cooperative area that can be allocated remains. The allocation of non-cooperation area radio resources to the non-cooperation area belonging user terminal 2 is continued. On the other hand, if there is no radio resource for the non-cooperative area that can be allocated (step S5, YES), the process proceeds to step S6.

  Step S6: The base station controller 10 refers to the logical resource table with respect to the base station 1 having no assignable radio resources for non-cooperative areas, and checks whether radio resources for cooperating areas that can be assigned still remain. As a result, when the radio resources for the cooperation area that can be allocated remain (step S6, YES), the process proceeds to step S7. On the other hand, if there is no radio resource for the cooperation area that can be allocated (step S6, NO), the processing in FIG. 6 is terminated.

  Step S7: The base station controller 10 allocates radio resources for the cooperation area to the user terminals 2 belonging to the non-cooperation area based on the result of step S1. At this time, in the logical resource table of the base station 1 that performs communication with the user terminal 2, the base station controller 10 leaves the number of slots corresponding to the radio resource amount necessary for the user terminal 2 as unallocated. Mapping is performed in the radio resource area of the area. Thereby, the amount of radio resources necessary for the user terminal 2 is ensured in the corresponding base station 1.

  Step S8: The base station controller 10 determines whether there is a radio resource that can be allocated. If there is a radio resource that can be allocated (step S8, YES), the process returns to step S7. On the other hand, when there is no radio resource that can be allocated (step S8, NO), the process of FIG. 6 is terminated.

  In the mapping to the logical resource table according to the present embodiment, as illustrated in FIG. 7, first, the base station cooperation communication portion is secured in the wireless resource area for the cooperation area, and then the non-base station cooperation communication portion is not cooperation. Secure in the area radio resource area. If there are surplus radio resources in the radio area for the cooperation area (unallocated area of the radio area for the cooperating area), the surplus radio resources in the radio area for the cooperating area are used for non-base station cooperative communication. To do. As described above, in the radio resource allocation according to the present embodiment, it is possible to efficiently use radio resources by performing the base station cooperation communication first and then performing the non-base station cooperation communication. This is because, for base station cooperative communication, a plurality of cooperative base stations 1 must secure a common radio resource, but for non-base station cooperative communication, if a single base station 1 allocates an unallocated radio resource. This is because the degree of freedom of radio resource allocation is greater for non-base station cooperative communication.

  The base station controller 10 sends the radio resource allocation result of the corresponding logical resource table to each base station 1 to be controlled.

  In step S1, if the user terminal 2 belongs to an area based on information (CINR, RSSI, etc.) indicating the radio reception quality from each base station 1 in the user terminal 2, due to the influence of fading, etc. It is expected that a user terminal 2 showing a combination of base stations different from the specified combination of base stations shown in FIG. 3 (a combination of three base stations performing base station cooperative communication) will appear. Examples of coping methods in this case (methods 1, 2, and 3) are shown below.

(Method 1)
A user terminal 2 indicating a combination of base stations different from the base station specified combination is treated as belonging to a non-cooperation area of the base station 1 to which the user terminal 2 is connected.

(Method 2)
First, for a user terminal 2 indicating a combination of base stations that is different from the prescribed combination of base stations, a predetermined number of base stations 1 included in the combination of the different base stations are selected from those having better radio reception quality. The base station 1 (here, two) is selected. The selected base station 1 is referred to as a selected base station 1, and the base station 1 that has not been selected is referred to as an unselected base station 1. Next, it is assumed that the user terminal 2 belongs to the cooperation area closer to the non-selected base station 1 having the worst wireless reception quality among a plurality (two in this case) of cooperation areas related to the two selected base stations 1. deal with. For example, it is assumed that the combination of base stations related to a certain user terminal 2 is the base stations A, B, and F in FIG. If the two base stations with better radio reception quality are the base stations A and B, the base with the worst radio reception quality among the two cooperative areas (Area 1 and 6) related to the base stations A and B is assumed. The user terminal 2 is assumed to belong to the cooperation area (Area 6) closer to the station F.

(Method 3)
A virtual area (Area 7) corresponding to a combination of base stations different from the specified combination of base stations (corresponding to Areas 1 to 6) is provided, and radio resources for Area 7 are prepared. A conceptual diagram of the logical resource table in this case is shown in FIG. As a result, the user terminal 2 indicating a combination of base stations different from the prescribed combination of base stations is treated as belonging to Area 7, and the radio for Area 7 of each base station 1 included in the combination of different base stations Allocate resources in common.

  According to this embodiment, by dividing a cell into a non-cooperation area and a cooperation area, and securing radio resources for each area in advance, each radio resource of base station cooperation communication and non-base station cooperation communication Allocation can be performed smoothly. As a result, a plurality of base stations cooperate with each other to communicate with one mobile station, thereby improving the communication quality of each mobile station and preventing a decrease in the utilization efficiency of radio resources in the entire cellular mobile communication system. It becomes like this.

  In addition, radio resources for base station cooperation communication are secured in the radio area for the cooperation area first, and then the surplus radio resources in the radio resource area for the cooperation area are used for non-base station cooperation communication, It can be expected that the utilization efficiency will be further improved.

  Also, by making the logical subchannel size allocated to each area variable, for example, logical subchannels can be dynamically set according to the degree of communication congestion in each area. As a result, it is possible to flexibly cope with the deviation of the required amount of radio resources caused by the deviation of the number of user terminals 2 in each area.

As mentioned above, although embodiment of this invention was explained in full detail with reference to drawings, the specific structure is not restricted to this embodiment, The design change etc. of the range which does not deviate from the summary of this invention are included.
For example, in the above-described embodiment, it is assumed that three base stations cooperate to perform base station cooperation communication, but the number of base station cooperation is not limited to this. For example, two base stations can cooperate to perform base station cooperation communication.

  FIG. 9 is a conceptual diagram illustrating a configuration example of a communication area (cell) when two base stations cooperate to perform base station cooperation communication. FIG. 9 shows a case where attention is paid to the base station A in the cell configuration of FIG. Each cell is divided into a cooperation area and a non-cooperation area. The cooperation area is an area that is a target of base station cooperation communication. The non-cooperation area is an area that is not a target of base station cooperation communication. In the example of FIG. 9, the cell 3A of the base station A is divided into one non-cooperation area (Area 0) and six cooperation areas (Area 1 to 6). Furthermore, the cooperation area (Area7-9) between the base stations adjacent to the base station A is provided. A cooperation area identifier (Area 1 to 9) is assigned to the cooperation area for each combination of cooperation base stations. Therefore, the geographical position to which each cooperation area identifier is assigned is different for each base station.

  The cooperation area is provided as an adjacent area between the cooperation target base stations for each combination of the cooperation target base stations. It is assumed that base station cooperation communication is performed between two adjacent base stations in a common cooperation area (cooperation area having the same identifier). In FIG. 9, for example, it is assumed that base station A and B perform base station cooperative communication in a common cooperative area (Area 6). The reason why the cooperation areas are divided into a plurality of areas is to classify the cooperation areas without contradiction based on the cell arrangement of the cellular mobile communication system. Therefore, what is necessary is just to determine how many cooperation areas are divided according to cell arrangement. Which area (non-cooperation area (Area 0) or any one of cooperation areas (Area 1 to 9)) the user terminal 2 is in is determined based on the position information of the user terminal 2, CINR or RSSI. be able to.

  Note that two cooperation areas in which two base stations cooperate to perform base station cooperation communication and three cooperation areas in which three base stations cooperate to perform base station cooperation communication may be mixed. In this case, the wireless resource area for 2 cooperation areas and the wireless resource area for 3 cooperation areas are divided on the frequency axis or on the time axis in the logical resource table, so that the above-described embodiment can be achieved. The same can be applied.

DESCRIPTION OF SYMBOLS 1 ... Base station, 2 ... Mobile station (user terminal), 10 ... Base station controller

Claims (4)

In a cellular mobile communication system in which a plurality of base stations are arranged and a continuous communication service area is constructed by the communication area of each base station, a base station control device that controls a plurality of base stations,
The communication area is divided into a cooperation area that is a target of base station cooperation communication and a non-cooperation area that is not a target of base station cooperation communication,
The base station controller is
In the radio resource area of each base station, radio resource management means for managing radio resources separately in radio resource areas for non-cooperative areas and radio resource areas for cooperating areas;
Area determination means for determining whether the mobile station is in a non-cooperation area or a cooperation area;
A radio resource to be allocated to a mobile station in a cooperative area is commonly secured in a radio resource area for a cooperative area of each base station that performs base station cooperative communication with the mobile station, and a radio resource to be allocated to a mobile station in a non-cooperative area Radio resource allocating means for securing a radio resource area for a non-cooperation area of a base station that communicates with the mobile station ,
The radio resource allocating means includes
A radio resource in the radio area for the cooperative area is allocated to a mobile station in the cooperating area of a base station, and then a radio in the radio resource area for the non cooperating area is assigned to a mobile station in the non-cooperative area of the base station. When resources are allocated, there is no radio resource that can be allocated to the radio resource area for the non-cooperation area of the base station, and there are surplus radio resources in the radio resource area for the cooperating area of the base station, Allocating the surplus radio resource to a mobile station in a non-cooperation area of the base station,
A base station controller characterized by that. In a cellular mobile communication system in which a plurality of base stations are arranged and a continuous communication service area is constructed by the communication area of each base station, a base station control device that controls a plurality of base stations,
The communication area is divided into a cooperation area that is a target of base station cooperation communication and a non-cooperation area that is not a target of base station cooperation communication,
The base station controller is
In the radio resource area of each base station, radio resource management means for managing radio resources separately in radio resource areas for non-cooperative areas and radio resource areas for cooperating areas;
Area determination means for determining whether the mobile station is in a non-cooperation area or a cooperation area;
A radio resource to be allocated to a mobile station in a cooperative area is commonly secured in a radio resource area for a cooperative area of each base station that performs base station cooperative communication with the mobile station, and a radio resource to be allocated to a mobile station in a non-cooperative area Radio resource allocating means for securing a radio resource area for a non-cooperation area of a base station that communicates with the mobile station,
The cooperation area is provided as an adjacent area between the cooperation target base stations for each prescribed combination of the cooperation target base stations,
Radio resources are prepared for each area,
The area discriminating unit is for determining an area to which the mobile station belongs based on information indicating radio reception quality from each base station in the mobile station, and the base station performs communication in cooperation with the base station. For a mobile station indicating a combination of base stations different from the specified combination, a plurality of predetermined base stations are selected from the base stations included in the combination of the different base stations from the one with the best radio reception quality, and these Among the multiple cooperation areas related to the selected base station, treat that the mobile station belongs to the cooperation area closer to the unselected base station with the worst wireless reception quality,
A base station controller characterized by that. In a cellular mobile communication system in which a plurality of base stations are arranged and a continuous communication service area is constructed by the communication area of each base station, a base station control method for controlling a plurality of base stations,
The communication area is divided into a cooperation area that is a target of base station cooperation communication and a non-cooperation area that is not a target of base station cooperation communication,
The radio resource area of each base station is divided into a radio resource area for non-cooperation areas and a radio resource area for cooperation areas,
Determining whether the mobile station is in a non-cooperating area or a cooperating area;
A step of commonly securing radio resources to be allocated to mobile stations in a cooperation area in a radio resource area for the cooperation area of each base station that performs base station cooperation communication with the mobile station;
Comprising the steps of a radio resource allocated to the mobile station in the uncoordinated area allocated in the non-cooperative area for radio resource area of the base station communicating with the mobile station, only including,
A radio resource in the radio area for the cooperative area is allocated to a mobile station in the cooperating area of a base station, and then a radio in the radio resource area for the non cooperating area is assigned to a mobile station in the non-cooperative area of the base station. When resources are allocated, there is no radio resource that can be allocated to the radio resource area for the non-cooperation area of the base station, and there are surplus radio resources in the radio resource area for the cooperating area of the base station, Allocating the surplus radio resource to a mobile station in a non-cooperation area of the base station,
And a base station control method. In a cellular mobile communication system in which a plurality of base stations are arranged and a continuous communication service area is constructed by the communication area of each base station, a base station control method for controlling a plurality of base stations,
The communication area is divided into a cooperation area that is a target of base station cooperation communication and a non-cooperation area that is not a target of base station cooperation communication,
The radio resource area of each base station is divided into a radio resource area for non-cooperation areas and a radio resource area for cooperation areas,
An area determination step for determining whether the mobile station is in a non-cooperation area or a cooperation area;
A step of commonly securing radio resources to be allocated to mobile stations in a cooperation area in a radio resource area for the cooperation area of each base station that performs base station cooperation communication with the mobile station;
Securing radio resources to be allocated to mobile stations in a non-cooperation area in a radio resource area for non-cooperation areas of a base station that communicates with the mobile station, and
The cooperation area is provided as an adjacent area between the cooperation target base stations for each prescribed combination of the cooperation target base stations,
Radio resources are prepared for each area,
The area determining step is to determine an area to which the mobile station belongs based on information indicating radio reception quality from each base station in the mobile station, and the base station performs communication in cooperation with the base station cooperative communication. For a mobile station indicating a combination of base stations different from the specified combination, a plurality of predetermined base stations are selected from the base stations included in the combination of the different base stations from the one with the best radio reception quality, and these Among the multiple cooperation areas related to the selected base station, treat that the mobile station belongs to the cooperation area closer to the unselected base station with the worst wireless reception quality,
And a base station control method.

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