WO2014154107A1

WO2014154107A1 - Grouping management method for tdd cross-interference, and base station

Info

Publication number: WO2014154107A1
Application number: PCT/CN2014/073730
Authority: WO
Inventors: 张晨璐; 刘峰; 高阳; 董贤东; 曹一卿
Original assignee: 东莞宇龙通信科技有限公司; 宇龙计算机通信科技(深圳)有限公司
Priority date: 2013-03-26
Filing date: 2014-03-19
Publication date: 2014-10-02
Also published as: CN103200577A; CN103200577B

Abstract

Provided is a grouping management method for TDD cross-interference, comprising: employing grouping based interference coordination technology to group multiple cells; and performing the following steps for multiple cells in the same group: A) selecting at least one interference isolation cell from the multiple cells in the same group; B) controlling the at least one interference isolation cell to isolate the other cells of the multiple cells in the same group, so as to group the other cells into multiple groups, each group containing at least one cell; the multiple groups employ the same or different TDD uplink and downlink subframe proportion configuration parameters. Also provided is a base station. The technical solution of the present invention utilizes some of the cells to isolate and regroup the other cells in the same group, thus allowing the cells in different groups after regrouping to use different TDD uplink and downlink subframe proportions for data transmission, and effectively controlling cross-interference.

Description

Packet management method and base station for TDD cross interference

Technical field

The present invention relates to the field of communications technologies, and in particular, to a packet management method for TDD cross interference and a base station. Background technique

In recent years, the new generation of wireless communication technology has developed rapidly. Compared with the third generation of wireless communication technology, the new generation of mobile communication technology has many advantages such as network architecture, small signal delay, high communication quality and fast speed. According to the classification of uplink and downlink service multiplexing, the new generation mobile communication technology can be divided into TDD (Time Division Duplex) system and FDD (Frequency Division Duplex) system. Compared with the FDD system, the TDD system is more efficient in utilizing system resources. The base station can use different radio frame structures of different uplink and downlink subframe ratios between base stations according to different uplink and downlink traffic. However, due to the existence of cross-interference, the existing TDD technology limits the flexible deployment of the downlink subframe ratio configuration on the TDD system. As shown in FIG. 1, if the base station 1 serves the terminal 1, and the base station 2 serves the terminal 2, when the base station 1 currently uses the downlink subframe 102 and the base station 2 currently uses the uplink subframe 104, except for the base station 1 and the terminal 1, the base station 2, the normal signal 2 between the terminal 2, and the interference signal 1 caused by different uplink and downlink configurations between the terminal 1 and the terminal 2, and between the base station 1 and the base station 2, that is, cross interference.

In order to solve this problem, the International Organization for Standardization (3GPP) launched the eMTA project (Additional enhancements to LTE Time Division Duplex (TDD) for Downlink-Uplink Interference Management and Traffic Adaptation) in May 2010, and researched the new version of UE (User Equipment, User). Equipment) How to implement service adaptation and interference management of the TDD system under the condition of hybrid networking with the old version of the UE, where the new version of the UE refers to the user terminal supporting the R12 (12th edition protocol) and subsequent protocol versions of the 3GPP, and the old version UE refers to the user end of the pre-R12 version protocols (such as R10, R11, etc.) that support 3GPP. End.

In order to avoid the performance loss caused by strong cross interference, 3GPP proposes a Cell Cluster Interference Mitigation (CCIM). When the base station is deployed, the scheme dynamically processes the cells according to the transmission loss or interference level between the base stations. Cells with low transmission loss or high inter-cell interference levels are grouped into one group; base stations with large transmission loss or small inter-cell interference levels are classified into different groups. All the base stations in the group must be configured with the same TDD uplink-downlink subframe ratio configuration to avoid strong cross-interference. Different groups can be configured with different TDD uplink-downlink subframe ratio configurations to adaptively uplink and downlink traffic load conditions. As shown in FIG. 3, for a plurality of cells served by the macro base station 302, after processing by CCIM technology, all cells in the packet 304, the packet 306, and the packet 308 must be configured to the same TDD configuration, and the packet 304, the packet Between the 306 and the packet 308, different TDD uplink and downlink subframe ratio configurations can be configured.

The CCIM scheme gives a valid TDD dynamic subframe proportional configuration interference avoidance method. After further research, it is found that in the isolated cell environment, because the cell is not affected by the cross-talk of the neighboring cell, the flexible and dynamic TDD uplink-downlink subframe ratio configuration can be completely configured according to its own uplink and downlink traffic load ratio. In the case of dynamically configured cell-intensive deployment, the dynamic configuration efficiency is low because the small-interval interference relationship is complex and interrelated. Moreover, the more cells included in a packet, the smaller the gain generated by dynamic configuration. As shown in "Packet 308" in Figure 3, since the 6 cells in the packet 308 maintain interrelated interference relations, if you want to avoid strong cross interference, you must configure 6 cells to be the same TDD uplink and downlink. Frame ratio. In this way, for each cell, it is inevitable that the flexible and dynamic TDD uplink and downlink subframe ratio configuration can be configured according to the ratio of its uplink and downlink traffic load as in the isolated cell, and the gain obtained by the dynamic configuration will be greatly reduced.

Therefore, in order to further improve the efficiency and flexibility of dynamic allocation of TDD uplink and downlink subframes, an efficient packet scheme is urgently needed to achieve more efficient TDD subframe dynamic configuration. Summary of the invention

The present invention is based on the above problems, and proposes a new technical solution, which can use some cells to isolate and re-group other cells in the same group, thereby supporting the re-grouping. The cells in the same group use different TDD uplink and downlink subframe ratios for data transmission, and effectively control cross interference.

In view of this, the present invention provides a packet management method for TDD cross interference, which includes: grouping multiple cells by using a packet-based interference coordination technique, and performing the following steps on multiple cells belonging to the same group: A) Selecting at least one interfering isolated cell from the plurality of cells in the same group; B) controlling the at least one interfering isolated cell to isolate the remaining ones of the plurality of cells in the same group to The cell is divided into a plurality of groups, and each of the groups includes at least one cell; wherein, the plurality of the groups adopt the same or different TDD uplink and downlink subframe proportion configuration parameters. In this technical solution, by setting an interference isolation cell, and by the interference isolation cell, the other cells in the same group are isolated and re-grouped, so that the obtained multiple groups become isolated "cells", which are not intersected by the neighboring cells. The impact of interference, so that flexible and dynamic TDD uplink and downlink subframe ratio configuration can be configured according to the ratio of its uplink and downlink traffic load (each group contains one or more cells, and the uplink and downlink subframe ratios of these cells are configured the same to avoid crossover. Interference).

In the above technical solution, preferably, the step of selecting at least one interference isolation cell from the multiple cells of the same group includes: acquiring an interference situation between base stations in the multiple cells in the same group; Establishing a cell interference topology structure corresponding to the interference situation, and selecting the at least one interference isolation cell based on the cell interference topology structure. In this technical solution, the interference relationship between the multiple cells can be clearly determined according to the cell interference topology, so that the cell in which the remaining cells can be isolated is selected as the interference isolated cell. Of course, the topology structure is only a specific form of relationship expression. Obviously, it can also be used to express the interference relationship between multiple cells by other means, such as forms, connections, and the like.

In the above technical solution, preferably, the step of acquiring the interference situation between the base stations in the multiple cells in the same group includes: calculating the same according to a propagation model of the multiple cells in the same group Coupling loss between base stations in a plurality of cells of the group as the interference condition; or obtaining the above according to the received cross-interference measurement between the base stations in the plurality of cells of the same group The cross-interference situation between the base stations in the same group and/or the cross-interference situation between the terminals in the above-mentioned cells as the interference situation. In this technical solution, in one case, the propagation model and theoretical calculation can be established at the initial stage of deployment, that is, the root According to the calculated coupling loss between the cell base stations, the interference situation is determined, and the process may have a certain deviation from the description of the interference environment. However, the solution realizes the single order, and only needs to complete the "key cell" selection through one-time measurement calculation in the initial stage of deployment. No need for later adjustments. In another case, after the network is completed, the cross-interference measurement is performed in the field to determine the interference condition according to the measurement result. This situation is slightly more complicated than the former case, but the interference environment includes the eNB (base station) to the eNB. The cross interference or / and the UE (user equipment, equivalent to the terminal) cross interference to the UE, so the described interference environment is more accurate.

In the above technical solution, preferably, the method further includes: determining, according to the cell interference topology structure, an interference relationship between each of the cells and other cells; and one of the cells having the largest number of interference relationships or A plurality of the isolated cells are used as the interference. In this technical solution, in a normal case, statistics can be made by the number of relationships in which each cell has interference with other cells, and it is used as a criterion for judging whether or not it is selected as an interference isolation cell. By recording the above criteria (of course, other standards can also be used), the base station or other device can automatically select the interference isolation cell; of course, the user can manually select the interference isolation cell according to the specified standard. At the same time, the base station or other equipment can compare and analyze the results of the automatic selection with the results manually selected by the user, thereby continuously correcting the above criteria, in order to achieve a more accurate and more suitable cell selection scheme.

In the foregoing technical solution, the step of isolating the remaining ones of the multiple cells in the same group by the at least one interference isolation cell includes: statically configuring the TDD uplink and downlink used by the at least one interference isolation cell The subframe ratio configuration parameter is configured to perform data transmission using only the subframe of the specified location; wherein each subframe of the specified location has the same data transmission direction in all radio frame structures defined in the TDD system . In the technical solution, a plurality of radio frame structures are defined in the TDD system, which includes 0 to 9 subframes in total, and in the different radio frame structures, the foregoing 10 subframes may be uplink subframes, downlink subframes, or special. Subframe; but in the already defined #0~#6 total 7 seed frame configuration parameters, the subframes with the sequence numbers 0, 1, 2, 5, and 6 are the same (where, for the subframe with sequence number 6) , in #0~#2, #6 is a special subframe, in #3~#5 is a downlink subframe, but since the special subframe can be used for downlink data transmission in any configuration, but only in In some configurations, uplink data transmission is allowed, so special subframes can be regarded as downlink subframes, and thus the interference is isolated by the cell. It is configured to use only those subframes with the same transmission direction for data transmission so as not to cause cross interference with cells in other groups.

In the above technical solution, the step of isolating the remaining ones of the multiple cells in the same group by the at least one interference isolation cell includes: dynamically configuring the TDD uplink and downlink used by the at least one interference isolation cell a subframe ratio configuration parameter; comparing a TDD uplink and downlink subframe ratio configuration parameter used by each of the at least one interference isolation cell and each of the groups; wherein, if the subframe of the specified location is used by the at least one interference isolation cell and at least One of the groups is used for different data transmission directions, and the at least one interference isolation cell is configured to disable the subframe of the specified location. In this technical solution, the uplink and downlink subframe proportion configuration parameters of the interference isolation cell are dynamically configured to make it more conform to the actual requirements of the interference isolation cell; and at the same time, by restricting interference to the subframe used by the isolated cell, for example, when a certain group uses #1 subframe configuration, when the interference isolation cell uses #2 subframe configuration, the interference isolation cell will be disabled with subframes of sequence numbers 3 and 8, to ensure that the cells in the above group are protected from cross interference, but other groups The uplink and downlink subframe proportion configuration parameters can be dynamically configured arbitrarily.

In the foregoing technical solution, preferably, the step of the at least one interference isolation cell isolating the remaining ones of the multiple cells in the same group includes:

Turning off the at least one interference isolation cell; or

Reducing coverage of the at least one interfering isolated cell, such that a coverage dead zone is formed between the at least one interfering isolated cell and all neighboring cells, or a repeated coverage area between the at least one interfering isolated cell and all neighboring cells The cross-interference strength in the medium is not greater than the preset interference intensity threshold, or the served terminal is not present in the repeated coverage area. In this technical solution, by physically reducing the coverage of the interfering isolated cell or directly closing the interference isolation cell, the "isolation band" is artificially constructed, so that multiple groups are physically separated to avoid cross interference. Or when the cross-interference of the repeated coverage area is small or there is no serviced terminal, it is obvious that the influence of cross-interference on the terminal can also be avoided. It should be noted that although the coverage of the interfering isolated cell is reduced or turned off, since the communication system uses the dynamic configuration of the base station and the macro base station hybrid network, the signal coverage of the terminal is not affected.

In the above technical solution, preferably, the reducing the at least one interference isolation cell The step of coverage includes at least one of the following or a combination thereof: adjusting signal transmit power of the base station in the at least one interfering isolated cell, adjusting an antenna height of the base station, and adjusting an antenna downtilt of the base station.

According to still another aspect of the present invention, a base station is further provided, comprising: a processing unit, grouping a plurality of cells by using a packet-based interference coordination technology, and selecting at least one interference isolation from a plurality of cells belonging to the same group a data exchange unit, configured to send isolation control signaling to the at least one interference isolation cell, thereby controlling the at least one interference isolation cell to isolate the remaining ones of the multiple cells in the same group, to The remaining cells are divided into multiple groups, and each of the groups includes at least one cell; wherein, the plurality of the groups adopt the same or different TDD uplink and downlink subframe proportion configuration parameters. In this technical solution, by setting an interference isolation cell, and by the interference isolation cell, the other cells in the same group are isolated and re-grouped, so that the obtained multiple groups become isolated "cells", which are not intersected by the neighboring cells. The impact of interference, so that flexible and dynamic TDD uplink and downlink subframe ratio configuration can be configured according to the ratio of its uplink and downlink traffic load (each group contains one or more cells, and the uplink and downlink subframe ratios of these cells are configured the same to avoid crossover. Interference).

In the foregoing technical solution, preferably, the processing unit further acquires an interference situation between the base stations in the multiple cells in the same group, establish a cell interference topology structure corresponding to the interference situation, and The cell interference topology structure selects the at least one interference isolated cell. In the technical solution, the interference relationship between the multiple cells can be clearly determined according to the cell interference topology, so that the cell in which the remaining cells can be isolated is selected as the interference isolation cell. Of course, the topology structure is only a specific form of relationship expression. Obviously, it can also be used to express interference relationships between multiple cells in other ways, such as forms, connections, and the like.

In the above technical solution, preferably, the processing unit calculates, according to a propagation model of the multiple cells of the same group, a coupling loss between the base stations in the multiple cells in the same group, as the Interference condition; or the data interaction unit receives a result of cross interference measurement between base stations in the plurality of cells in the same group; and the processing unit acquires the same group according to the result of the cross interference measurement The cross-interference situation between the base stations in the base station and/or the cross-interference situation between the terminals in the above-mentioned cells as the interference situation. In the technical side In the case, in one case, the propagation model and theoretical calculation can be established at the initial stage of deployment, and the interference situation can be determined according to the calculated coupling loss between the cell base stations, and the process has a certain deviation from the description of the interference environment, but The solution realizes the single order, and only needs to complete the "key cell" selection by one-time measurement calculation in the initial stage of deployment, and does not require post-adjustment. In another case, after the network is completed, cross-interference measurement is performed in the field to determine the interference condition according to the measurement result. This situation is slightly more complicated than the former case, but the interference environment includes cross-interference from eNB to eNB. Or / and UE to UE cross interference, so the described interference environment is more accurate.

In the above technical solution, preferably, the processing unit further determines, according to the cell interference topology structure, an interference relationship between each of the cells and other cells, and the cell with the largest number of interference relationships exists. One or more of the interference isolated cells. In this technical solution, in the normal case, statistics can be made by the number of relationships in which each cell interferes with other cells, and it is used as a criterion for judging whether or not it is selected as an interference isolation cell. By recording the above criteria (of course, other standards can also be used), the base station or other device can automatically select the interference isolation cell; of course, the user can manually select the interference isolation cell according to the specified standard. At the same time, the base station or other equipment can compare and analyze the results of the automatic selection with the results manually selected by the user, thereby continuously correcting the above criteria, in order to achieve a more accurate and more suitable cell selection scheme.

In the above technical solution, preferably, the isolation control signaling includes static configuration information, where the static configuration information is used to statically configure a TDD uplink and downlink subframe proportional configuration parameter used by the at least one interference isolation cell, so that The data transmission is configured to use only the subframes of the specified location; wherein each of the subframes of the specified location has the same data transmission direction in all radio frame structures defined in the TDD system. In the technical solution, a plurality of radio frame structures are defined in the TDD system, which includes a total of 10 subframes from 0 to 9. In different radio frame structures, the foregoing 10 subframes may be uplink subframes, downlink subframes, or special. Subframe; but in the already defined #0~#6 total 7 seed frame configuration parameters, the subframes with the sequence numbers 0, 1, 2, 5, and 6 are the same (where, for the subframe numbered 6) , in #0~#2, #6 is a special subframe, in #3~#5 is a downlink subframe, but since the special subframe can be used for downlink data transmission in any configuration, but only in In some configurations, uplink data transmission is allowed, so special subframes can be regarded as downlink subframes, and thus the interference isolation cells are configured to use only these transmission directions. Data transmission is performed at the same subframe so that it does not cause cross interference with cells in other groups. In the above technical solution, preferably, the isolation control signaling includes dynamic configuration information, where the dynamic configuration information is used to: dynamically configure the at least one interference isolation cell to use

The TDD uplink and downlink subframe ratio configuration parameter, and the at least one interference isolation cell is compared with the TDD uplink and downlink subframe ratio configuration parameter used by each of the groups; wherein, if the subframe of the specified location is An interfering isolated cell and at least one of the groups are used for different data transmission directions, and the at least one interfering isolated cell is configured to disable the subframe of the designated location. In this technical solution, the uplink and downlink subframe proportion configuration parameters of the interference isolation cell are dynamically configured to make it more conform to the actual requirements of the interference isolation cell; and at the same time, by restricting interference to the subframe used by the isolated cell, for example, when a certain group uses #1 subframe configuration, when the interference isolation cell uses #2 subframe configuration, the interference isolation cell will be disabled with subframes of sequence numbers 3 and 8, to ensure that the cells in the above group are protected from cross interference, but other groups The uplink and downlink subframe proportion configuration parameters can be dynamically configured arbitrarily.

In the foregoing technical solution, preferably, the isolation control signaling includes range adjustment information, where the range adjustment information is used to:

Turning off the at least one interference isolation cell; or

Controlling reducing coverage of the at least one interfering isolated cell such that a coverage hole is formed between the at least one interfering isolated cell and all neighbor cells, or repeating coverage between the at least one interfering isolated cell and all neighbor cells The cross-interference strength in the area is not greater than the preset interference strength threshold, or the served terminal is not present in the repeated coverage area. In this technical solution, by physically reducing the coverage of the interfering isolated cell or directly closing the interference isolation cell, the "isolation band" is artificially constructed, so that multiple groups are physically separated to avoid cross interference. Or when the cross-interference of the repeated coverage area is small or there is no serviced terminal, it is obvious that the influence of cross-interference on the terminal can also be avoided. It should be noted that although the coverage of the interference isolation cell is reduced or turned off, since the communication system uses the dynamic configuration of the base station and the macro base station hybrid network, the signal coverage of the terminal is not affected.

In the above technical solution, preferably, the range adjustment information is used to control a parameter of adjusting a base station in the at least one interference isolation cell, where the parameter includes at least one of the following or a group thereof And a signal transmission power of the base station, an antenna height of the base station, and an antenna downtilt angle of the base station.

In the above technical solution, preferably, the base station is an a macro base station corresponding to the multiple cells, or a designated dynamic configuration base station.

With the above technical solution, the cells in the same group can be isolated and re-grouped by using the partial cell, so that the cells in different groups after the re-grouping use different TDD uplink-downlink subframe ratios for data transmission, and are effective. Control cross interference. DRAWINGS

1 is a schematic structural view of a TDD system in the related art;

2 is a schematic structural view showing seven radio frames in a TDD system defined in the related art;

3 is a schematic diagram of grouping cells by using a packet-based interference coordination technique in the related art;

4 shows a flow chart of a packet management method for TDD cross interference according to an embodiment of the present invention;

Figure 5 shows a block diagram of a base station in accordance with an embodiment of the present invention;

6 shows a schematic diagram of group management of a cell according to an embodiment of the present invention; FIG. 7 shows a flow chart of dynamically selecting a "key cell" according to an embodiment of the present invention; FIG. 8 shows a diagram according to the present invention. Schematic diagram of a cell interference topology structure of an embodiment; FIG. 9 shows a flow chart for statically selecting a "key cell" according to an embodiment of the present invention; FIG. 10 shows a coverage by narrowing a base station according to an embodiment of the present invention. Range to form a schematic of interference isolation. detailed description

The above described objects, features and advantages of the present invention will be more fully understood from the following detailed description. It should be noted that, in the case of no conflict, the features in the embodiments and the embodiments of the present application may be combined with each other.

In the following description, numerous specific details are set forth in order to provide a thorough understanding of the invention. The present invention may be embodied in other specific forms than those described herein. Therefore, the scope of the present invention is not limited by the specific embodiments disclosed below.

4 is a flow chart showing a packet management method for TDD cross interference according to an embodiment of the present invention.

As shown in FIG. 4, a packet management method for TDD cross-interference according to an embodiment of the present invention includes: Step 402: Group multiple cells by using a packet-based interference coordination technology; Step 404, for multiple groups belonging to the same group The cells perform the following steps: A) selecting at least one interfering isolated cell from the plurality of cells of the same group; B) controlling the at least one interfering isolated cell to the remaining cells of the plurality of cells in the same group Performing isolation to divide the remaining cells into multiple groups, each of the groups including at least one cell; wherein, the plurality of the groups adopt the same or different TDD uplink and downlink subframe proportion configuration parameters. In this technical solution, by setting an interference isolation cell, and by the interference isolation cell, the other cells in the same group are isolated and re-grouped, so that the obtained multiple groups become isolated "cells", which are not intersected by the neighboring cells. The impact of interference, so that flexible and dynamic TDD uplink and downlink subframe ratio configuration can be configured according to the ratio of its uplink and downlink traffic load (each group contains one or more cells, and the uplink and downlink subframe ratios of these cells are configured the same to avoid crossover. Interference).

In the above technical solution, preferably, the step of acquiring the interference situation between the base stations in the multiple cells in the same group includes: calculating the same according to a propagation model of the multiple cells in the same group Coupling loss between base stations in a plurality of cells of the group as the interference condition; or obtaining the above according to the received cross-interference measurement between the base stations in the plurality of cells of the same group Cross-interference between base stations in the same group and/or on The cross-interference between the terminals in the cell is taken as the interference situation. In this technical solution, in one case, the propagation model and the theoretical calculation can be established at the initial stage of deployment, and the interference situation can be determined according to the calculated coupling loss between the cell base stations, and the process has a certain deviation from the description of the interference environment. However, the program realizes the single order, and only needs to complete the "key cell" selection by one-time measurement calculation in the initial stage of deployment, and does not require post-adjustment. In another case, after the network is completed, the cross-interference measurement is performed in the field to determine the interference condition according to the measurement result. This situation is slightly more complicated than the former case, but the interference environment includes the eNB (base station) to the eNB. The cross interference or / and the UE (user equipment, equivalent to the terminal) cross interference to the UE, so the described interference environment is more accurate.

In the foregoing technical solution, the step of isolating the remaining ones of the multiple cells in the same group by the at least one interference isolation cell includes: statically configuring the TDD uplink and downlink used by the at least one interference isolation cell The subframe ratio configuration parameter is configured to perform data transmission using only the subframe of the specified location; wherein each subframe of the specified location has the same data transmission direction in all radio frame structures defined in the TDD system . In the technical solution, a plurality of radio frame structures are defined in the TDD system, which includes 0 to 9 subframes in total, and in the different radio frame structures, the foregoing 10 subframes may be uplink subframes, downlink subframes, or special. Subframe; but in the already defined #0~#6 total 7 seed frame configuration parameters, the subframes with the sequence numbers 0, 1, 2, 5, and 6 are the same (where, for the subframe with sequence number 6) , in #0~#2, #6 is a special subframe, in #3~#5 is a downlink subframe, but because of the special subframe In any configuration, it can be used for downlink data transmission, but only allows uplink data transmission in some configurations, so special subframes can be regarded as downlink subframes, and thus the interference isolation cells are configured to use only these transmission directions. Data transmission is performed at the same subframe so that it does not cause cross interference with cells in other groups.

Turning off the at least one interference isolation cell; or

Reducing coverage of the at least one interfering isolated cell, such that a coverage dead zone is formed between the at least one interfering isolated cell and all neighboring cells, or a repeated coverage area between the at least one interfering isolated cell and all neighboring cells The cross-interference strength in the medium is not greater than the preset interference intensity threshold, or the served terminal is not present in the repeated coverage area. In this technical solution, by physically reducing the coverage of the interfering isolated cell or directly closing the interference isolation cell, the "isolation band" is artificially constructed, so that multiple groups are physically separated to avoid cross interference. Or when the cross-interference of the repeated coverage area is small or there is no serviced terminal, it is obvious that the influence of cross-interference on the terminal can also be avoided. It should be noted that although the coverage of the interfering isolated cell becomes smaller or is closed, since the communication system uses a dynamic configuration of the hybrid base station and the macro base station, the signal coverage of the terminal is not affected. cover.

In the above technical solution, preferably, the step of reducing coverage of the at least one interference isolation cell comprises at least one of the following or a combination thereof: adjusting signal transmission power of a base station in the at least one interference isolation cell, Adjusting an antenna height of the base station and adjusting an antenna downtilt angle of the base station.

Figure 5 shows a block diagram of a base station in accordance with an embodiment of the present invention.

As shown in FIG. 5, a base station 500 according to an embodiment of the present invention includes: a processing unit 502, grouping a plurality of cells by using a packet-based interference coordination technology, and selecting at least one of a plurality of cells belonging to the same group. Interference-isolated cell; the data interaction unit 504, sends the isolation control signaling to the at least one interfering isolated cell, so as to control the at least one interfering isolated cell to isolate the remaining cells in the same group of the plurality of cells, And dividing the remaining cells into multiple groups, each of the groups including at least one cell; wherein, the plurality of the groups adopt the same or different TDD uplink and downlink subframe proportion configuration parameters. In this technical solution, by setting an interference isolation cell, and by the interference isolation cell, the other cells in the same group are isolated and re-grouped, so that the obtained multiple groups become isolated "cells", which are not intersected by the neighboring cells. The impact of interference, so that flexible and dynamic TDD uplink and downlink subframe ratio configuration can be configured according to the ratio of its uplink and downlink traffic load (each group contains one or more cells, and the uplink and downlink subframe ratios of these cells are configured the same to avoid crossover. Interference).

In the above technical solution, preferably, the processing unit 502 further acquires an interference situation between the base stations in the multiple cells in the same group, and establishes a cell interference topology structure corresponding to the interference situation, and is based on the The cell interference topology structure selects the at least one interference isolated cell. In this technical solution, the interference relationship between the multiple cells can be clearly determined according to the cell interference topology, so that the cell in which the remaining cells can be isolated is selected as the interference isolation cell. Of course, the topology structure is only a specific form of relationship expression. Obviously, it can also be used to express the interference relationship between multiple cells in other ways, such as forms, connections, and the like.

In the foregoing technical solution, the processing unit 502 is configured to calculate, according to a propagation model of the multiple cells of the same group, a coupling loss between the base stations in the multiple cells in the same group. Interference condition; or the data interaction unit 504 receives the same group a result of cross-interference measurement between base stations in another plurality of cells; and the processing unit 502 acquiring, according to the result of the cross-interference measurement, a cross-interference situation between the base stations in the same group and/or in the foregoing cell The cross-interference situation between the terminals is taken as the interference situation. In this technical solution, in one case, the propagation model and the theoretical calculation can be established at the initial stage of deployment, and the interference situation can be determined according to the calculated coupling loss between the cell base stations, and the process has a certain deviation from the description of the interference environment. However, the program realizes the single order, and only needs to complete the "key cell" selection by one-time measurement calculation in the initial stage of deployment, and does not require post-adjustment. In another case, after the network is completed, cross-interference measurement is performed in the field to determine the interference condition according to the measurement result. This situation is slightly more complicated than the former case, but the interference environment includes the cross-drying of the eNB to the eNB. 4 especially or / and UE to UE cross-dry, so the description of the dry environment is more accurate.

In the foregoing technical solution, preferably, the processing unit 502 further determines, according to the cell interference topology structure, an interference relationship between each of the cells and other cells, and the cell with the largest number of interference relationships exists. One or more of the ones are used as the interference isolation cell. In this technical solution, in a normal case, statistics can be made by the number of relationships in which each cell interferes with other cells, and it is used as a criterion for judging whether or not it is selected as an interference isolation cell. By recording the above criteria (of course, other standards can also be used), the base station or other device can automatically select the interference isolation cell; of course, the user can manually select the interference isolation cell according to the specified standard. At the same time, the base station or other equipment can compare and analyze the results of the automatic selection with the results manually selected by the user, thereby continuously correcting the above criteria, in order to achieve a more accurate and more suitable cell selection scheme.

In the above technical solution, preferably, the isolation control signaling includes static configuration information, where the static configuration information is used to statically configure a TDD uplink and downlink subframe proportional configuration parameter used by the at least one interference isolation cell, so that The data transmission is configured to use only the subframes of the specified location; wherein each of the subframes of the specified location has the same data transmission direction in all radio frame structures defined in the TDD system. In the technical solution, a plurality of radio frame structures are defined in the TDD system, which includes a total of 10 subframes from 0 to 9. In different radio frame structures, the foregoing 10 subframes may be uplink subframes, downlink subframes, or special. Subframe; but in the already defined #0~#6 total 7 seed frame configuration parameters, the subframes with sequence numbers 0, 1, 2, 5, 6 The same is true (where, for the subframe with sequence number 6, it is a special subframe in #0~#2, #6, and a downlink subframe in #3~#5, but because of the special subframe, no matter what The configuration can be used for downlink data transmission, but only allows uplink data transmission in some configurations, so special subframes can be regarded as downlink subframes. Therefore, the interference isolation cells are configured to use only the same transmission direction. Data is transmitted at the frame so that it does not interfere with cells in other groups.

In the above technical solution, preferably, the isolation control signaling includes dynamic configuration information, where the dynamic configuration information is used to: dynamically configure a TDD uplink and downlink subframe proportion configuration parameter used by the at least one interference isolation cell, and Controlling, by the at least one interfering isolated cell, a TDD uplink and downlink subframe proportion configuration parameter that is used by each of the groups, and wherein the subframe of the specified location is used by the at least one interference isolation cell and at least one of the groups For different data transmission directions, the at least one interference isolation cell is configured to disable the subframe of the specified location. In this technical solution, the uplink and downlink subframe proportion configuration parameters of the interference isolation cell are dynamically configured to make it more conform to the actual requirements of the interference isolation cell; and at the same time, by restricting interference to the subframe used by the isolated cell, for example, when a certain group uses #1 subframe configuration, when the interference isolation cell uses #2 subframe configuration, the interference isolation cell will be disabled with subframes of sequence numbers 3 and 8, to ensure that the cells in the above group are protected from cross interference, but other groups The uplink and downlink subframe proportion configuration parameters can be dynamically configured arbitrarily.

Turning off the at least one interference isolation cell; or

Controlling reducing coverage of the at least one interfering isolated cell such that a coverage hole is formed between the at least one interfering isolated cell and all neighbor cells, or repeating coverage between the at least one interfering isolated cell and all neighbor cells The cross-interference strength in the area is not greater than the preset interference strength threshold, or the served terminal is not present in the repeated coverage area. In this technical solution, by physically reducing the coverage of the interfering isolated cell or directly closing the interference isolation cell, the "isolation band" is artificially constructed, so that multiple groups are physically separated to avoid cross interference. Or when the cross-interference of the repeated coverage area is small or there is no serviced terminal, it is obvious that the influence of cross-interference on the terminal can also be avoided. It should be noted that although the coverage of the interference isolation cell becomes smaller or is closed, since the communication system uses Dynamically configuring the hybrid network between the base station and the macro base station, and thus does not affect the signal coverage of the terminal.

In the above technical solution, preferably, the range adjustment information is used to control a parameter for adjusting a base station in the at least one interference isolation cell, where the parameter includes at least one of the following or a combination thereof: a signal transmission power of the base station, The antenna height of the base station and the antenna downtilt angle of the base station.

In the foregoing technical solution, preferably, the base station 500 is a macro base station corresponding to the multiple cells, or a designated dynamically configured base station.

According to the description of the background of the present invention, the currently proposed CCIM technology groups, for example, multiple cells in the same macro base station coverage, and different uplink and downlink subframe ratio configuration parameters may be used for cells in different groups; In the case of cells in the same group, especially in the case where the number of cells included in the same group is large and dense, such as the packet 308 shown in FIG. 3, the cells in the packet 308 are dynamically configured. The gain will be greatly suppressed.

In order to enable the cells in the same group to implement dynamic configuration of multiple parameters, the present invention proposes a scheme for regrouping cells in an existing packet, which may also be called "group splitting", that is, the original CCIM-based The resulting packets are "split" to get more groups, and each group becomes isolated. These groups can use the same or different uplink and downlink subframe ratio configuration parameters.

Specifically, taking the packet 308 shown in FIG. 3 as an example, as shown in FIG. 6, according to the original grouping method, 6 cells will be classified into one due to strong cross interference between Cell 1 and 6. Group, Celll to 6 must use the same TDD subframe configuration, otherwise cross interference will occur. According to the topology analysis, the interference relationship between Cell 3 and Cell 4 is the most complicated, and it has strong cross interference with Cell 1, 2, 4 and Cell 5, 6, and 3, respectively. Therefore, Cell 3 and/or Cell 4 are selected as the key cell 602, and an artificial "interfering isolation band" is formed at Cell3 and/or Cell4 (Cell4 in the figure), thereby splitting the remaining Cell into two groups. , ie Group A and Group B.

Therefore, in order to achieve the above process, the present invention needs to solve the following two problems:

1) How to determine the "key cell" (corresponding to the embodiment described in the corresponding examples of Figures 4 and 5) "Interference isolation cell");

2) How to form an "interference zone" through "key cells".

For the problem 1), two specific modes proposed in the present invention will be respectively described below with reference to Figs. 7 to 9.

As shown in Figure 7, one way is to dynamically select the "key cell". The specific process includes:

Step 702, cross interference measurement and reporting. Here, "cross-interference measurement" refers to eNB-to-eNB and/or UE-to-UE cross-interference generated between dynamically configured base stations within a dynamic configuration range.

Among them, the measurement of cross interference can be performed periodically or event triggered. The period of the interference measurement can be consistent with the dynamic configuration period (used to configure the TDD uplink and downlink subframe ratio configuration parameters), or it can be greater or less than the dynamic configuration period. In order to reduce the signaling overhead caused by interference measurement, the measurement of cross-interference can also be triggered by an event, such as when the topology of the dynamically configured base station changes (new base station is turned on or the base station is turned off).

For eNB-to-eNB interference, a threshold value T _{eNB is set} . When the signal transmitted by the base station A is received by the base station B, the reception level is greater than or equal to the threshold T _eNB , and the base station B is considered to be strongly cross-interrupted to the base station A. On the other hand, if it is less than the threshold value T _eNB , it is considered that the interference can be tolerated. For the interference from the UE to the UE, a certain threshold value T _{UE is set} , when the signal sent by any UE to which the base station A belongs is received by any UE to which the base station B belongs, and the receiving level strength is greater than or equal to the threshold value T _UE It is considered that there is strong cross interference between the base station B and the base station A; on the contrary, when it is less than the threshold value T _UE , it is considered that the cross interference between the base station B and the base station A can be tolerated.

A "central control node" may be established, which may specifically be a macro base station corresponding to the cell or a dynamically configured base station in a designated cell, so that the central control node summarizes and analyzes the measurement results from the respective dynamically configured base stations. Specifically, when data interaction between the central control node and each dynamically configured base station is performed, the information interaction interface, such as the X2 interface, may be implemented, for example:

■ Redefine dedicated X2 signaling.

The country defines a new information domain in the existing X2 related signaling, such as "eNB Configuration Update" signaling defines a new information field.

Step 704, the reconstruction of the interference topology structure and the determination of the "key cell", that is, determining the "key cell" by establishing an interference topology structure.

Specifically, for example, the central control node obtains the interference relationship list shown in the following table by using all the measurement results received (where 1 represents Celel shown in FIG. 6, and so on):

Table 1

According to the above table, a corresponding "interference topology structure" can be established, as shown in Fig. 8, so that the "key cell" to be selected can be determined according to the "interference topology structure".

Further, when selecting a key cell, it needs to be satisfied that: the cell has more interference relationships with other cells; and the cell (or possibly other selected cells) may be selected as a "key cell". At the time, all "key cells" can ensure that the remaining cells are divided into multiple groups. For example, in Figure 8, when the cell No. 3 is selected as the "key cell", the remaining cells are divided into two groups, one group includes cells No. 1 and No. 2, and the other group includes cells No. 4, No. 5 and No. 6. .

Step 706, similar to the above process, implements "re-split" of the cells in the original group, and obtains a plurality of new groups.

Step 708: Configure a "key cell" to implement interference isolation for the multiple groups. At the same time, use the existing TDD reconfiguration algorithm to perform independent dynamic subframe configuration for each group. If the "cross interference measurement" is triggered, the process returns to step 702, and the above steps are repeated.

As shown in Figure 9, another way is to statically select a "key cell". The specific process includes:

Step 902: At the initial stage of network construction, coupling loss (Coupling Loss) between dynamically configured cells is obtained by model measurement and theoretical calculation.

The above coupling loss mainly includes large-scale loss between base stations and antenna feed loss at the transmitting end and the receiving end. The above measurement calculation is completed by the manual calculation and evaluation in the initial stage of network construction. Specifically, a certain threshold value TL is set. _Ss , when the coupling loss of the base station A to the base station B is less than the threshold value TL. _{When ss} , it is considered that there is a strong possibility of cross interference between base station A and base station B; when base station A is connected to base station B The loss is greater than the threshold T _L . _{At SS} , it is considered that there is no possibility of strong cross interference between base station A and base station B.

Step 904, reconstructing the "loss topology" and determining the "key cell" according to the structure. The list of loss relationships obtained according to the manual measurement calculation is shown in Table 1. The reconstructed "loss topology" is shown in Figure 8, so that the "key cell" is determined accordingly.

Step 906: According to the determination of the "key cell", the "re-split" of the remaining cells is implemented, which is similar to the step 706 shown in FIG. 7, and details are not described herein again.

Step 908: Configure a "key cell" to implement interference isolation for the multiple groups. At the same time, use the existing TDD reconfiguration algorithm to perform independent dynamic subframe configuration for each group. If the "coupling loss measurement" is triggered, the process returns to step 902, and the above steps are repeated.

The above describes the dynamic and static methods to determine the "key cell". among them:

The static "key cell" selection only considers the coupling loss between the base stations, and does not consider the impact on the actual interference caused by dynamic factors such as fast decay and human loss; meanwhile, the method only considers the cross interference of the eNB to the eNB, Consider the cross interference of the UE to the UE. Therefore, the static "key cell" selection will have a certain deviation from the description of the interference environment. However, the scheme realizes the single-segment, and only needs to complete the "key cell" selection by one-time measurement calculation in the initial stage of deployment, without the need for later adjustment.

The dynamic "key cell" selection uses real-time inter-base station cross-interference measurements to describe the inter-station interference environment, where the interference environment includes cross-interference from the eNB to the eNB or/and cross-interference from the UE to the UE. Therefore, the described interference environment is more accurate than the static “key cell” option. However, this method is more complicated than the static "key cell" selection implementation, and requires cross-interference measurement between base stations as support.

For the problem 2), the three specific ways proposed in the present invention are respectively described below.

Mode 1 "Interference isolation based on static scheduling restrictions"

The scheme refers to statically configuring a "key cell" into a TDD configuration defined by the protocol, and restricting the user to perform data transmission only in subframes with sequence numbers 0, 1, 2, 5, 6 through scheduling. The subframe is in an idle state.

It can be seen from FIG. 2 that for the seven TDD uplink and downlink subframe ratio configurations defined by the existing system, All configured subframes with sequence numbers 0, 1, 2, 5, and 6 are all in the same transmission direction. Therefore, data transmission on these subframes does not cause cross interference due to different transmission directions regardless of the configuration of the neighboring cell. In addition to the subframes other than the foregoing subframes, the base station will disable uplink and downlink data scheduling. Therefore, no matter how the neighboring cell dynamically configures the TDD uplink and downlink subframe ratio, it will not cross interference with the "cross interference isolation zone". Thereby achieving the independence of the inter-group interference environment after the split.

Method 2 "Interference isolation based on dynamic scheduling restrictions"

The scheme refers to the TDD uplink and downlink subframe configuration of the "key cell" is also dynamically configured. When the data transmission direction of a certain subframe of the "key cell" is inconsistent with the neighboring cell, the scheduling is performed at the subframe of the "key cell" base station. The method prohibits scheduling uplink or downlink data.

The TDD uplink and downlink subframe configuration adopted by the "key cell" in "Dynamic Scheduling Limit" can be dynamically changed. When the "key cell" sub-frame direction is inconsistent with the neighboring cell, for example, in Figure 6, if the split group A adopts TDD configuration #2, the group B adopts TDD configuration #4, and at this time, the "key cell" Cell4 adopts the TDD configuration. #2, in addition to the subframes with sequence numbers 0, 1, 2, 5, 6, the subframes with sequence numbers 4, 8, and 9 can also be used to schedule downlink user data.

In mode 2, the TDD configuration used by the "key cell" can be dynamically adjusted according to its own uplink and downlink traffic load ratio, or it can follow packet A or packet B - the same dynamic change.

The "dynamic scheduling limit" of mode 2 is more flexible than the "static scheduling limit" of scheme one, providing more available resources for "key cells". However, due to the need for TDD configuration information used by neighboring cells, additional information interaction is required.

Method 3 "Impact isolation based on coverage reduction"

The scheme refers to adjusting the coverage of the base station by using the method of downlink power control, base station antenna height or downtilt angle adjustment, thereby achieving the effect of isolating cross interference.

As shown in FIG. 10, by narrowing the coverage of the base station in the key cell from the range A to the range B, the key cell and the group A and the group B are artificially formed to form a coverage gap of the cell base station, thereby forming an interference isolation band. Achieve interference isolation for Group A and Group B.

Of course, since the TDD dynamic configuration is mainly applied to the dynamic configuration of the base station and the macro base station hybrid networking scenario, adjusting the coverage of the "key cell" does not affect the message to the UE. Number coverage.

The technical solution of the present invention is described in detail above with reference to the accompanying drawings. In the related art, only the same uplink and downlink subframe proportion configuration parameters can be used for cells in the same group, which limits the gain when dynamic configuration is used. The present invention provides a packet management method for TDD cross-interference and a base station, which can use some cells to isolate and re-group other cells in the same group, thereby supporting cell use in different groups after re-grouping. Different TDD uplink and downlink subframe ratios are used for data transmission, and cross interference is effectively controlled.

The above is only the preferred embodiment of the present invention, and is not intended to limit the present invention, and various modifications and changes can be made to the present invention. Any modifications, equivalent substitutions, improvements, etc. within the spirit and scope of the invention are intended to be included within the scope of the invention.

Claims

Claim

A packet management method for TDD cross-interference, comprising: grouping a plurality of cells by using a packet-based interference coordination technique, and performing the following steps on a plurality of cells belonging to the same group:

A) selecting at least one interference isolation cell from the plurality of cells in the same group;

B) controlling the at least one interference isolation cell to isolate the remaining ones of the multiple cells in the same group, to divide the remaining cells into multiple groups, each of the groups including at least one cell;

The same or different TDD uplink and downlink subframe proportion configuration parameters are used between the multiple groups.

The method of group management of TDD cross-interference according to claim 1, wherein the step of selecting at least one interference-isolated cell from the plurality of cells in the same group comprises:

Obtaining interference between base stations in multiple cells in the same group;

Establishing a cell interference topology corresponding to the interference condition, and selecting the at least one interference isolation cell based on the cell interference topology.

The packet management method for TDD cross-interference according to claim 2, wherein the step of acquiring interference between base stations in the plurality of cells in the same group comprises:

Calculating a coupling loss between base stations in the plurality of cells in the same group as the interference condition according to a propagation model of the plurality of cells in the same group;

Or obtaining, according to the result of the cross-interference measurement between the base stations in the plurality of cells in the same group, the cross-interference situation between the base stations in the same group and/or the intersection between the terminals in the foregoing cell. The interference situation is taken as the interference situation.

4. The method for group management of TDD cross-interference according to claim 2, further comprising:

Determining an interference relationship between each of the cells and other cells according to the cell interference topology; One or more of the cells having the largest number of interference relationships are used as the interference isolated cells.

The packet management method for TDD cross-interference according to any one of claims 1 to 4, wherein the at least one interference-isolated cell isolates the remaining ones of the plurality of cells in the same group The steps include:

Statically configuring the TDD uplink and downlink subframe proportion configuration parameter used by the at least one interference isolation cell to be configured to use only the subframe of the specified location for data transmission;

Wherein, each of the subframes of the specified location has the same data transmission direction in all radio frame structures defined in the TDD system.

Dynamically configuring a TDD uplink and downlink subframe proportion configuration parameter used by the at least one interference isolation cell;

Comparing the TDD uplink and downlink subframe ratio configuration parameters used by the at least one interference isolation cell and each of the groups respectively;

And if the subframe of the specified location is used by the at least one interference-isolating cell and the at least one group for different data transmission directions, configuring the at least one interference-isolated cell to disable the subframe of the specified location.

The method for managing a TDD cross-interference packet according to any one of claims 1 to 4, wherein the at least one interfering isolated cell isolates the remaining ones of the plurality of cells in the same group The steps include:

Turning off the at least one interference isolation cell; or

Reducing the coverage of the at least one interfering isolated cell such that the at least one interfering isolated cell and all neighboring cells form a blind spot not covered by the respective base station, or between the at least one interfering isolated cell and all neighboring cells The cross-interference strength in the repeated coverage area is not greater than the preset interference strength threshold, or the area of the served terminal is not present in the repeated coverage area.

The method for group management of TDD cross-interference according to claim 7, wherein the step of reducing coverage of the at least one interference-blocking cell comprises at least one of the following or a combination thereof:

Adjusting a signal transmission power of the base station in the at least one interference isolation cell, adjusting an antenna height of the base station, and adjusting an antenna downtilt angle of the base station.

A base station, comprising:

Processing unit, grouping multiple cells by using a packet-based interference coordination technology, and selecting at least one interference isolation cell from multiple cells belonging to the same group;

The data interaction unit sends the isolation control signaling to the at least one interference isolation cell, so as to control the at least one interference isolation cell to isolate the remaining cells of the multiple cells in the same group, so as to isolate the remaining cells. Divided into a plurality of groups, each of which contains at least one cell;

The base station according to claim 9, wherein the processing unit further acquires interference between base stations in the plurality of cells in the same group, and establishes a cell interference topology corresponding to the interference situation. Structure, and selecting the at least one interference isolated cell based on the cell interference topology.

11. The base station according to claim 10, characterized in that

The processing unit calculates, according to a propagation model of the plurality of cells in the same group, a coupling loss between the base stations in the plurality of cells in the same group as the interference situation;

Or the data interaction unit receives a result of cross interference measurement between base stations in the plurality of cells in the same group; and the processing unit acquires the base station in the same group according to the result of the cross interference measurement The inter-interference situation and/or the cross-interference between the terminals in the above-mentioned cell as the interference situation.

The base station according to claim 10, wherein the processing unit further determines an interference relationship between each of the cells and other cells according to the cell interference topology, and the interference relationship exists. One or more of the most numerous cells are used as the interference isolated cell.

The base station according to any one of claims 9 to 12, wherein the isolation control signaling includes static configuration information, and the static configuration information is used to statically configure the at least one interference isolation cell. TDD uplink and downlink subframe proportion configuration parameters, so that it is configured to use only the subframes of the specified location for data transmission;

The base station according to any one of claims 9 to 12, wherein the quarantine control signaling includes dynamic configuration information, where the dynamic configuration information is used to:

Dynamically configuring a TDD uplink and downlink subframe proportion configuration parameter used by the at least one interference isolation cell, and controlling the at least one interference isolation cell to compare a TDD uplink and downlink subframe ratio configuration parameter used by each of the at least one interference isolation cell;

The base station according to any one of claims 9 to 12, wherein the isolation control signaling includes range adjustment information, and the range adjustment information is used for:

Turning off the at least one interference isolation cell; or

Controlling reducing coverage of the at least one interfering isolated cell such that a coverage hole is formed between the at least one interfering isolated cell and all neighbor cells, or repeating coverage between the at least one interfering isolated cell and all neighbor cells The cross-interference strength in the area is not greater than the preset interference strength threshold, or the served terminal is not present in the repeated coverage area.

The base station according to claim 15, wherein the range adjustment information is used to control a parameter of adjusting a base station in the at least one interference-isolated cell, the parameter comprising at least one of the following or a combination thereof:

a signal transmission power of the base station, an antenna height of the base station, and an antenna downtilt angle of the base station.

The base station according to any one of claims 9 to 12, wherein the base station is a macro base station corresponding to the plurality of cells, or a designated dynamically configured base station.