JP5497714B2 - Wireless communication method and wireless communication system - Google Patents

Description

  The present invention provides cooperative interference control scheduling for avoiding interference between radio communication sets when there are a large number of sets of radio base stations and radio communication apparatuses (hereinafter referred to as “radio communication sets”) communicating with each other in a small area. The present invention relates to a wireless communication method and a wireless communication system.

  In order to realize simultaneous communication of a plurality of wireless communication sets, there is a cooperative interference control technique using multiple antennas. The multi-antenna cooperative interference control technique is a technique in which a plurality of antennas are installed in a radio base station and a radio communication apparatus, respectively, and interference is controlled by signal processing. In order to reduce mutual interference between the wireless communication sets, signal processing is performed in cooperation between the wireless communication sets. Specific technologies include inter-cell interference control (Non-Patent Document 1) and Interference Alignment (Non-Patent Document 2, Non-Patent Document 3). System throughput is improved by cooperative control technology using multiple antennas.

G.J.Foschini, K.Karakayali and R.A.Valenzuela, “Coordinating multiple antenna cellular networks to achieve enormous spectral efficiency”, IEE Proc. Commun., Vol.153, No.4, pp.548-555, Aug. 2006. V.R.Cadambe, S.A.Jafar, “Interference Alignment and Degrees of Freedom of the K-User Interference Channel”, IEEE Trans. On Information Theory, Vol.54, No.8, Aug. 2008 S.W.Peters, R.W.Heath, Jr., “Cooperative Algorithm for MIMO Interference Channels”, IEEE Trans. On Vehicular Technology, Vol.60 No.1, Jan. 2011

  When there are a large number of wireless communication sets in a narrow area, it is not always possible for all wireless communication sets to cooperate and perform simultaneous communication. This is because, in the case of cooperative interference control technology using multiple antennas, the number of wireless communications that can be simultaneously communicated is limited by the number of antennas installed in the wireless base station and the wireless communication device.

  That is, the cooperative interference control is configured to control directivity by controlling the amplitude / phase, etc., for the signals transmitted from the antenna elements constituting the multi-antenna by the radio base station and the radio communication device of each radio communication set. Then, reception is performed by directing null toward the direction in which the interference wave arrives, and transmission is performed by directing null to surrounding wireless communication sets so that interference does not occur. In the directivity pattern, the number of directions in which the null can be directed depends on the number of antenna elements. Therefore, as the number of antenna elements increases, the direction in which nulls can be directed increases, and the number of wireless communication sets that can communicate simultaneously increases. For example, when N antennas are installed in the radio base station and the radio communication device of each radio communication set, the maximum number of simultaneous communications is (N-1) communication in inter-cell interference control and (2N in Interference Alignment). -1) Until communication. On the other hand, in such an environment, when there are more communications at the same time, the interference cannot be reduced by the cooperative interference control technology, and all communications cannot be performed simultaneously.

  When there are a large number of communications in this way, the above problem can be solved by grouping the wireless communication sets to reduce the number of simultaneous wireless communication sets to be equal to or less than the maximum number of simultaneous communication, and transmitting the groups in a time division manner between the groups. Can be solved. Here, as a grouping method, for a wireless communication set that is used in a geographically fixed manner, a method of grouping each wireless communication set in advance can be considered. That is, when configuring the wireless communication system, each wireless communication set is grouped with the maximum number of simultaneous communication or less, and communication is performed while assigning a time zone in which each group communicates. However, the grouping method in advance cannot cope with environmental changes such as when the wireless communication set moves, when a new wireless communication set is generated, or when the wireless communication set leaves the communication range.

  An object of the present invention is to provide a radio communication method and a radio communication system that enable cooperative interference control for avoiding interference between radio communication sets even when there are changes in grouped radio communication sets.

  A first invention is composed of a plurality of radio base stations connected to a fixed radio base station and a plurality of radio communication devices connected to the radio base station, and a set of radio base stations and radio communication devices that communicate with each other. In a wireless communication method in which each wireless communication set performs communication while avoiding mutual interference using a cooperative interference control technique when a wireless communication set is used, the fixed wireless base station is a wireless base station that constitutes the wireless communication set A step of acquiring a smaller number of installed antennas of each of the wireless communication devices as the minimum number of installed antennas of the wireless communication set, a step of grouping combinations of wireless communication sets having the same minimum number of installed antennas, When the number of wireless communication sets exceeds the maximum number of simultaneous communication within the group according to the minimum number of antennas installed in the group The sub-group in which the number of wireless communication sets is equal to or less than the maximum number of communications, and the schedule information and the group or sub-group each assigned a period for performing communication in units of groups or sub-groups for each time slot in time division multiplex communication Generating information on radio communication sets belonging to the subgroup, and notifying the radio base stations constituting each radio communication set and the radio communication device, and the radio base stations and radio communication devices constituting the radio communication set are: A directivity pattern that acquires the period during which the local station transmits or receives based on the schedule information and the radio communication set information that belongs to each group or subgroup, and does not cause interference in other radio communication sets assigned to the same period To transmit or receive a data signal using.

  In the wireless communication method of the first invention, the step of obtaining the minimum number of installed antennas includes the step of obtaining the number of installed antennas of each of the wireless base station and the wireless communication device, and the wireless base station constituting the wireless communication set and the wireless Determining the smaller number of installed antennas of each communication device as the minimum number of installed antennas of the wireless communication set.

  A second invention is composed of a plurality of radio base stations connected to a fixed radio base station and a plurality of radio communication devices connected to the radio base station, and a set of radio base stations and radio communication devices that communicate with each other. In a wireless communication system in which each wireless communication set performs communication while avoiding mutual interference using a cooperative interference control technique when a wireless communication set is used, the fixed wireless base station is a wireless base station that constitutes the wireless communication set The combination of the minimum installed antenna number acquisition means for acquiring the smaller number of installed antennas of each of the wireless communication apparatuses as the minimum installed antenna number of the wireless communication set and the wireless communication set having the same minimum installed antenna number as one group And the number of wireless communication sets in the group is the maximum that can simultaneously communicate in the group according to the minimum number of antennas installed in the group. If the number of communications exceeds the number of wireless communication sets, the grouping means that constitutes a subgroup in which the number of communications is equal to or less than the maximum number of communications, and each time slot in time division multiplex communications communicates in units of each group or subgroup. A wireless communication system comprising: schedule information for assigning a period for performing communication and information on a wireless communication set belonging to each group or subgroup, and transmitting to a wireless base station constituting each wireless communication set and a wireless communication device; The wireless base station and wireless communication device that make up the set acquire the period during which the local station transmits or receives from the schedule information and the information of the wireless communication set belonging to each group or subgroup. Data signal using directivity pattern that does not cause interference in the wireless communication set of Comprising means for transmitting or receiving.

  In the radio communication system of the second invention, the minimum installed antenna number acquiring means includes an installed antenna number acquiring means for acquiring the installed antenna numbers of the radio base station and the radio communication apparatus, and a radio base station constituting the radio communication set. And a minimum number of installed antennas determining means for determining the smaller number of installed antennas of each wireless communication apparatus as the minimum number of installed antennas of the wireless communication set.

  In the wireless communication method and the wireless communication system of the present invention, the fixed wireless base station collects the minimum number of installed antennas included in each wireless communication set, and groups each wireless communication set according to the minimum number of installed antennas. As a result, each wireless communication set appropriately selects another wireless communication set that can perform cooperative interference control, and interference avoidance by cooperative interference control becomes possible.

It is a figure which shows the structural example of the radio | wireless communications system of this invention. It is a figure which shows the communication sequence in this invention. It is a figure which shows self-information. It is a figure which shows communication information. 2 is a diagram illustrating a configuration example of wireless communication devices 301 to 306. FIG. It is a figure which shows the structural example of radio base stations 201-205. FIG. 2 is a diagram showing a configuration example of a fixed radio base station 101. It is a figure which shows a group management information creation flow. It is a figure which shows a communication information list. It is a figure which shows a cooperation permission / prohibition list. It is a figure which shows group management information.

FIG. 1 shows a configuration example of a wireless communication system of the present invention.
In FIG. 1, the radio communication system can communicate with radio base stations 201 to 205 that can communicate with the fixed radio base station 101 and each radio base station 201 to 205 within the communication range of one fixed radio base station 101. Wireless communication devices 301 to 306. The radio base station 201 and the radio communication device 301 can communicate, the radio base station 202 and the radio communication device 302 can communicate, the radio base station 203 and the radio communication device 303 can communicate, and the radio base station 204 and The wireless communication device 304 can communicate, and the wireless base station 205 and the wireless communication devices 305 and 306 can communicate with each other to form a wireless communication set. In addition, when there are a plurality of communicable wireless communication devices 305 and 306 like the wireless base station 205, each is handled as an individual wireless communication set. Or you may handle as one radio | wireless communication set according to the direction with few installation antennas.

  The wireless communication devices 301 to 306 exchange data signals with an external network such as the Internet via the wireless base stations 201 to 205. In addition, in order to suppress interference between other wireless base stations and wireless communication devices that are close to each other, the wireless communication devices 301 to 306 can perform cooperative interference control (described later) in the wireless communication device, and the number of installed antennas. And the MAC address information are transmitted to the radio base stations 201 to 205, and the cooperative interference control is performed using the group management information that is the information about the group to which the radio communication apparatus belongs, which is received from the radio base stations 201 to 205. .

  The radio base stations 201 to 205 relay data signals between the radio communication devices 301 to 306 and the external network. Also, the radio base stations 201 to 205 relate to the information on whether or not the cooperative interference control is received, the number of installed antennas and the MAC address received from the wireless communication devices 301 to 306, and whether the cooperative interference control is possible, the number of installed antennas and the MAC address. Together with the information, the information is transmitted to the fixed radio base station 101, and the group management information received from the fixed radio base station 101 is transmitted to the radio communication devices 301 to 306, and cooperative interference control is performed using the group management information.

  The fixed radio base station 101 creates group management information using information received from the radio base stations 201 to 205, and transmits the group management information to the radio base stations 201 to 205.

  The cooperative interference control in the present invention is realized by the following five steps. A communication sequence in this cooperative interference control is shown in FIG.

  In the first step, the wireless communication device 301 notifies the wireless base station 201, which is the communication partner, of information on whether or not cooperative interference control is possible, the number of installed antennas, and the MAC address at a certain period or when communication is started. This information is self-information. FIG. 3 shows an example of self information.

In the second step, the radio base station 201 notifies the fixed radio base station 101 as a set of information by combining its own information and the self information of the radio communication device 301 notified from the radio communication device 301. . This set of information is communication information. FIG. 4 shows an example of communication information.
The second step is performed at regular intervals or when the radio base station 201 receives communication information from the radio communication device 301. Further, the radio base station 201 may notify communication information using a beacon signal.

  The first step and the second step are similarly performed in the radio base stations 201 to 205 and the radio communication devices 301 to 306.

  In the third step, the fixed radio base station 101 groups the radio base stations 201 to 205 and the radio communication devices 301 to 306 based on each communication information to create group management information.

  In the fourth step, the fixed radio base station 101 notifies the radio base stations 201 to 205 of group management information.

  In the fifth step, the radio base stations 201 to 205 notify the radio communication apparatuses 301 to 306 of the group management information notified from the fixed radio base station 101.

  In the fourth step and the fifth step, the fixed radio base station 101 uses signals that can be received by the radio base stations 201 to 205 and the radio communication devices 301 to 306, and the radio base station and the radio communication device in one step. Group management information may be shared.

  As described above, the self-information of the radio base stations 201 to 205 and the radio communication devices 301 to 306 is aggregated in the fixed radio base station 101, and the fixed radio base station 101 is grouped based on the aggregated self-information, By creating and disseminating group management information, the group management information is shared with each of the radio base stations 201 to 205 and the radio communication apparatuses 301 to 306. Each of the radio base stations 201 to 205 and the radio communication devices 301 to 306 performs simultaneous communication using the radio communication set of the same group according to the scheduling information added to the group management information.

FIG. 5 shows a configuration example of the wireless communication devices 301 to 306.
In FIG. 5, wireless communication devices 301 to 306 include an antenna unit 31, a reception processing unit 32, a transmission processing unit 33, an information input / output unit 34, a group management information storage unit 35, a self information storage unit 36, and a cooperative interference control processing unit. 37.

  The information input / output unit 34 exchanges data with an information terminal (computer or the like) to which the wireless communication device is connected. The transmission processing unit 33 is a transmission for outputting the data signal input from the information terminal via the information input / output unit 34 and the control signal input from the self-information storage unit 36 as a radio signal via the antenna unit 31. Processing (modulation, frequency conversion, etc.) is performed.

  The reception processing unit 32 demodulates the radio signal input via the antenna unit 31, extracts the data signal or the control signal, and depending on the type of the signal, the information input / output unit 34 or the group management information storage unit 35 Output to either of these. Of the signals input to the reception processing unit 32, signals to be output to the information terminal are output to the information input / output unit 34, and group management information is output to the group management information storage unit 35.

  The group management information storage unit 35 stores the input group management information, updates it every time new group management information is input, and outputs it to the cooperative interference control processing unit 37. The self information storage unit 36 stores the self information and outputs it to the transmission processing unit 33. The cooperative interference control processing unit 37 uses the information input from the group management information storage unit 35 to output information on the wireless communication device and the wireless base station having the same group ID to the transmission processing unit 33 and the reception processing unit 32. .

  The transmission processing unit 33 and the reception processing unit 32 are applied to a radio communication apparatus and a radio base station having the same group ID input from the cooperative interference control processing unit 37, and are based on an inter-cell interference control or interference alignment method. The directivity pattern is calculated, a directional beam of the directivity pattern is formed, and transmission processing or reception processing is performed.

FIG. 6 shows a configuration example of the radio base stations 201 to 205.
In FIG. 6, radio base stations 201 to 205 include an antenna unit 21, a reception processing unit 22, a transmission processing unit 23, an information input / output unit 24, a group management information storage unit 25, a self information storage unit 26, and a communication information connection unit 27. The cooperative interference control processing unit 28 is provided.

  The information input / output unit 24 exchanges data with an external network (such as the Internet) to which the wireless base station is connected. The transmission processing unit 23 is a transmission for outputting the data signal input from the external network via the information input / output unit 24 and the control signal input from the communication information connecting unit 27 via the antenna unit 21 as radio signals. Processing (modulation, frequency conversion, etc.) is performed.

  The reception processing unit 22 demodulates a radio signal input via the antenna unit 21, extracts a data signal or a control signal, and according to the type of the signal, an information input / output unit 24, a group management information storage unit 25 Or to the communication information linking unit 27. Of the signals input to the reception processing unit 22, signals to be output to the external network are sent to the information input / output unit 24, group management information is sent to the group management information storage unit 25, and self-information of the wireless communication device is communication information. It is output to the connecting unit 27.

  The group management information storage unit 25 stores the input group management information, updates the group management information every time new group management information is input, and outputs the updated group management information to the cooperative interference control processing unit. The self information storage unit 26 stores the self information and outputs it to the communication information connecting unit 27. The communication information connecting unit 27 connects the self information input from the self information storage unit 26 and the self information of the wireless communication device input from the reception processing unit 22 to create communication information, and outputs the communication information to the transmission processing unit 23.

  The cooperative interference control processing unit 28 uses the information input from the group management information storage unit 25 to output information on the wireless communication device and the wireless base station having the same group ID to the transmission processing unit 23 and the reception processing unit 22. .

  The transmission processing unit 23 and the reception processing unit 22 have the same group ID input from the cooperative interference control processing unit 28, and are applied to a radio communication apparatus and a radio base station as antennas based on inter-cell interference control or interference alignment techniques. The directivity pattern is calculated, a directional beam of the directivity pattern is formed, and transmission processing or reception processing is performed.

FIG. 7 shows a configuration example of the fixed radio base station 101.
In FIG. 7, the fixed radio base station 101 includes an antenna unit 11, a reception processing unit 12, a transmission processing unit 13, a communication information list creation unit 14, a cooperation availability list creation unit 15, a group management information creation unit 16, a group scheduling unit 17 Is provided.

  The transmission processing unit 13 performs transmission processing for outputting the signal (group management information including group scheduling information) input from the group scheduling unit 17 as a radio signal via the antenna unit 11.

  The reception processing unit 12 demodulates the radio signal input via the antenna unit 11, extracts communication information, and outputs the communication information to the communication information list creation unit 14. The communication information list creation unit 14 creates a communication information list from the communication information input from the reception processing unit 12, and outputs the communication information list to the cooperation availability list creation unit 15. The cooperation availability list creation unit 15 creates a cooperation availability list from the communication information list input from the communication information list creation unit 14, and outputs the cooperation availability list to the group management information creation unit 16.

  The group management information creation unit 16 creates group management information from the cooperation availability list input from the cooperation availability list creation unit 15 (described later) and outputs the group management information to the group scheduling unit 17. The group scheduling unit 17 refers to each group ID included in the group management information input from the group management information creation unit 16, schedules each group to create scheduling information, and adds the group management information to the transmission process. Output to part 13.

  Here, the creation of the group management information in the fixed radio base station 101 is performed as follows. The group management information creation flow is shown in FIG.

  In FIG. 8, the fixed radio base station 101 lists each piece of communication information input to the communication information list creation unit 14 as shown in FIG. 9 (S1). This list is a communication information list. Each row in the list represents a wireless communication device and a wireless base station that constitute each wireless communication set, and indicates a MAC address, cooperative interference control availability, and the number of installed antennas, respectively.

  Next, the cooperation availability list creation unit 15 refers to the availability of cooperative interference control included in the communication information list, and the wireless communication set (wireless base station and wireless communication device) included in the row of the communication information list performs cooperative interference control. If possible, each communication information is classified as being collaborative, and otherwise not collaborating, and is listed as shown in FIG. 10 (S2 to S5). This list is a cooperation availability list.

  Next, the group management information creation unit 16 refers to the cooperation availability list, and sets the minimum number of installation antennas of the wireless communication set (wireless base station and wireless communication device) that can be cooperated to the minimum installation of the wireless communication set. Select the number of antennas, and arrange and group them for each minimum number of antennas installed (S6). Here, it is determined whether or not the number of intra-group communications, which is the number of wireless communication sets of each group, is equal to or less than the maximum number of communications corresponding to the minimum number of installed antennas (S7). Note that the maximum number of communications that can be simultaneously communicated within one group is determined depending on what cooperative interference control method the wireless communication system uses. For example, when the minimum number of antennas is N, (N-1) communication is used for inter-cell interference control according to the prior art, and (2N-1) communication is used for interference alignment.

  When the number of intra-group communications exceeds the maximum number of communications (S7: No), it is divided into a plurality of subgroups that do not exceed the maximum number of communications (S8). On the other hand, when the number of intra-group communications is less than the maximum number of communications (S7: Yes), the group is not divided. For the grouped wireless communication sets including the subgroups as described above, the minimum number of installed antennas is set as a group ID (S9), and is listed as shown in FIG. The creation work is finished using this list as group management information (S10). In FIG. 11, for example, there are two wireless communication sets with group ID = 3, but the minimum number of antennas is 3, and the maximum number of communication in each of the cooperative interference control methods is 2 or 5. Simultaneous communication of the wireless communication set is possible. That is, it is not necessary to divide into subgroups.

  Finally, the group scheduling unit 17 adds different transmission timing information for each group to each group of the group management information. This transmission timing information is information on time slots assigned to each group.

  As described above, the wireless communication devices 301 to 306 and the wireless base stations 201 to 205 periodically transmit self-information and communication information to the fixed wireless base station 101, and update the group management information in the fixed wireless base station 101. The updated group management information is transmitted to the wireless communication devices 301 to 306 and the wireless base stations 201 to 205. As a result, even if the radio communication apparatuses 301 to 306 and the radio base stations 201 to 205 move, it is possible to appropriately change the group that performs the cooperative interference control. Further, by adding scheduling information to group management information in fixed radio base station 101, communication can be performed while avoiding interference between groups.

  In the above description, the communication information connecting unit 27 of the radio base stations 201 to 205 links the self-information of the subordinate radio communication device and the self-information of the radio base station itself to form the communication information shown in FIG. An example of transmitting to the fixed radio base station 101 is shown. The fixed radio base station 101 creates a communication information list shown in FIG. 9 from communication information received from each of the radio base stations 201 to 205, further creates a cooperation availability list shown in FIG. The procedure for creating group management information arranged and grouped according to the number of antennas was shown. Here, the communication information linking unit 27 of the radio base stations 201 to 205 recognizes whether or not the cooperative interference control of each radio communication set is possible, the minimum number of antennas, and the radio communication device and the radio base station that configure the radio communication set. The fixed radio base station 101 may be notified as communication information together with the MAC antenna. In this case, the fixed radio base station 101 can also group the radio communication sets based on the minimum number of installed antennas from the communication information and create the group management information shown in FIG.

11 Antenna section
12 Reception processor
13 Transmission processor
14 Communication information list generator
15 Cooperation availability list creation part
16 Group management information creation department
17 Group scheduling section
21 Antenna
22 Reception processor
23 Transmission processor
24 Information input / output section
25 Group management information storage
26 Self-information storage unit
27 Communication Information Connection Department
28 Cooperative interference control processor
31 Antenna section
32 Reception processor
33 Transmission processor
34 Information input / output section
35 Group management information storage
36 Self-information storage unit
37 Cooperative interference control processor
101 Fixed radio base station
201 to 205 Radio base station
301-306 wireless communication device

Claims (4)

Composed of a plurality of radio base stations connected to a fixed radio base station and a plurality of radio communication devices connected to the radio base station, and a set of radio base stations and radio communication devices communicating with each other is defined as a radio communication set In addition, in the wireless communication method in which each wireless communication set performs communication while avoiding mutual interference using cooperative interference control technology,
The fixed radio base station is
Acquiring the smaller number of installed antennas of each of the wireless base station and the wireless communication device constituting the wireless communication set as the minimum number of installed antennas of the wireless communication set;
A combination of the wireless communication sets having the same minimum installed antenna number as one group;
When the number of the wireless communication sets in the group exceeds the maximum number of communications that can be simultaneously communicated within the group according to the minimum number of antennas installed in the group, the number of wireless communication sets is equal to or less than the maximum number of communications. Sub-group steps,
For each time slot in time division multiplex communication, generate schedule information to which a period of communication is assigned and information on radio communication sets belonging to each group or sub group in each group or sub group unit, and configure each radio communication set And notifying the radio base station and the radio communication device,
The radio base station and the radio communication device constituting the radio communication set acquire a period during which the local station transmits or receives the schedule information and information of the radio communication set belonging to each group or subgroup, A wireless communication method comprising a step of transmitting or receiving a data signal using a directivity pattern that does not cause interference in another wireless communication set assigned in the same period. The wireless communication method according to claim 1,
Obtaining the minimum number of installed antennas,
Obtaining the number of installed antennas of each of the radio base station and the radio communication device;
Determining the one with the smaller number of installed antennas of each of the radio base station and the radio communication device constituting the radio communication set as the minimum number of installed antennas of the radio communication set. Composed of a plurality of radio base stations connected to a fixed radio base station and a plurality of radio communication devices connected to the radio base station, and a set of radio base stations and radio communication devices communicating with each other is defined as a radio communication set In addition, in a wireless communication system in which each wireless communication set performs communication while avoiding mutual interference using cooperative interference control technology,
The fixed radio base station is
Minimum installed antenna number acquisition means for acquiring the smaller number of installed antennas of each of the wireless base station and the wireless communication device constituting the wireless communication set as the minimum installed antenna number of the wireless communication set;
A combination of the wireless communication sets having the same minimum number of installed antennas is configured as one group, and the number of the wireless communication sets in the group can be simultaneously communicated within the group according to the minimum number of installed antennas of the group. When exceeding the maximum communication number, grouping means constituting a subgroup in which the number of wireless communication sets is equal to or less than the maximum communication number; and
For each time slot in time division multiplex communication, generate schedule information to which a period for communication is assigned and information on wireless communication sets belonging to each group or sub group in each group or sub group, and Comprising the radio base station to be configured and schedule means for transmitting to the radio communication device,
The radio base station and the radio communication device constituting the radio communication set acquire a period during which the local station transmits or receives the schedule information and information of the radio communication set belonging to each group or subgroup, A wireless communication system comprising means for transmitting or receiving a data signal using a directivity pattern that does not cause interference in another wireless communication set assigned in the same period. The wireless communication system according to claim 3,
The minimum number of installed antennas obtaining means is
Installed antenna number obtaining means for obtaining the number of installed antennas of each of the wireless base station and the wireless communication device;
A minimum installed antenna number determining means for determining, as a minimum installed antenna number of the wireless communication set, a smaller number of installed antennas of each of the wireless base station and the wireless communication device constituting the wireless communication set; Wireless communication system.

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