WO2013107121A1

WO2013107121A1 - Method and system for eliminating inter-cell interference

Info

Publication number: WO2013107121A1
Application number: PCT/CN2012/074209
Authority: WO
Inventors: 李毅; 谢忠时
Original assignee: 中兴通讯股份有限公司
Priority date: 2012-01-18
Filing date: 2012-04-17
Publication date: 2013-07-25
Also published as: CN102547994A

Abstract

Disclosed is a method for eliminating inter-cell interference, the method including: configuring more than one virtual cell on a base station, and configuring more than two physical cells for each virtual cell, wherein each physical cell acts as a cell partition (CP), and configuring cell-level public resources shared by all the CPs in each virtual cell; and when performing a service, according to the current wireless link state, the base station determining a CP from the virtual cell to which a terminal belongs, and sending and receiving service data according to the determined CP. Disclosed at the same time is a system for eliminating inter-cell interference. Applying the method and system of the present invention can effectively eliminate inter-cell interference, thus improving the throughput of a long-term evolution (LTE) system.

Description

Method and system for eliminating inter-cell interference

The present invention relates to Long Term Evolution (LTE) technology, and more particularly to a method and system for eliminating inter-cell interference. Background technique

Research on LTE systems includes some areas that are generally considered important, such as: reduced latency, increased user data rates, improved system capacity and coverage, and lower operating costs. The key to solving these problems is how to minimize the interference in the LTE system; here, the interference in the LTE system mainly comes from interference between cells.

In the LTE system, since the downlink uses Orthogonal Frequency Division Multiple Access (OFDMDMA) transmission technology, the uplink uses single carrier frequency division multiple access (SC-FDMA, Single Carrier-Frequency Division Multiple Access). Transmission technology, therefore, it is not possible to eliminate interference between cells by, for example, a spread spectrum method like the code division multiple access (CDMA) transmission technology. At the same time, in order to improve the spectrum utilization rate, it is not possible to simply adopt a frequency reuse method with a multiplexing factor of 3 or 7 in the Global System of Mobile communication (GSM). Therefore, in the LTE system, how to minimize the interference of the interval has become a research hotspot.

At present, in the LTE system, there are mainly three methods for reducing the interval interference, namely: interference randomization, interference cancellation, and interference coordination/avoidance. The interference randomization method refers to: using cell-specific scrambling and cell-specific interleaving, where the cell-specific interleaving is an interleaving multiple access known to those skilled in the art; or, using a frequency hopping method. The method of cell-specific scrambling and cell-specific interleaving is adopted. Because only the interference of 'j and interval is randomized, although the interference of the interval can be reduced to a certain extent, the method cannot be well eliminated. In addition to inter-cell interference, and the complexity of the system will be greatly increased; the method of frequency hopping will also greatly increase the complexity of the system. The method of interference cancellation refers to: relying on the spatial suppression of the terminal multi-antenna reception and the detection/subtraction-based elimination method, the method needs to rely on terminal support. The method of interference coordination/avoiding refers to: coordinating between cells to limit the allocation method of downlink resources, for example: obtaining a signal to noise ratio and a cell by limiting the time-frequency domain resources and transmission power allocation of neighboring cells The performance improvement of the boundary data rate and coverage, because the interference coordination/avoiding method limits the downlink resource allocation, it tends to reduce the spectrum utilization. In addition, the base station adopts a beamforming antenna method, and in the downlink direction, the interference of the interval can be reduced.

It can be seen from the above description that the above methods for reducing the interval interference have a certain degree of defects. Therefore, how to better eliminate inter-cell interference and improve the performance of edge users is an urgent problem to be solved in the LTE system. Summary of the invention

In view of this, the main object of the present invention is to provide a method and system for eliminating inter-cell interference, which can effectively eliminate interference between cells and further improve the throughput of the LTE system.

In order to achieve the above object, the technical solution of the present invention is achieved as follows:

The present invention provides a method for eliminating inter-cell interference, the method comprising:

Configuring one or more virtual cells on the base station, and configuring two or more physical cells for each virtual cell, each physical cell serving as a cell partition (CP, Cell Portion), and configuring all CP shared cells in each virtual cell. Level public resources;

When performing the service, the base station determines the CP from the virtual cell to which the terminal belongs according to the current radio link status, and performs transmission and reception of the service data through the determined CP.

In the above solution, the base station determines the CP from the virtual cell to which the terminal belongs according to the current radio link status, and is:

The base station determines the CP from the virtual cell to which the terminal belongs according to the currently measured signal strength of the terminal on each CP in the virtual cell. In the above solution, the base station determines the CP from the virtual cell to which the terminal belongs according to the signal strength of the terminal in the virtual cell, which is obtained by the current measurement, as follows:

The base station compares the currently measured signal strength of the terminal on each CP in the virtual cell with the set threshold, and determines the CP in the virtual cell whose signal strength exceeds the threshold as the current terminal. Activate the CP collection.

In the above solution, the method further includes:

The base station compares the signal strength of each terminal of the terminal in the virtual cell with the set threshold value, and updates the terminal by using the CP in the virtual cell whose signal strength exceeds the threshold value. The current active CP collection.

In the above solution, the sending and receiving of the service data by using the determined CP is: the base station sends the service data to each CP in the determined active CP set of the terminal, and simultaneously sends the data to the terminal. ;

The base station combines and demodulates the service data sent by the terminal received on each CP in the currently activated CP set of the terminal to obtain the service data sent by the terminal.

In the above solution, the method further includes: when it is required to send the control channel information, and/or the cell common information, the base station sends the control channel information, and/or the cell common information to each CP in the virtual cell, and simultaneously sends the information to the Said terminal.

The present invention also provides a system for eliminating inter-cell interference, the system comprising: a configuration unit and a base station;

a configuration unit, configured to configure one or more virtual cells on the base station, and configure two or more physical cells for each virtual cell, each physical cell as a CP, and configure all CPs in each virtual cell to share cell-level common resources ;

The base station is configured to: when the service is performed, the base station determines the CP from the virtual cell to which the terminal belongs according to the current radio link status, and performs transmission and reception of the service data by using the determined CP.

In the above solution, the base station is further configured to: when the control channel information needs to be sent, and/or the cell For public information, the control channel information, and/or the cell common information are transmitted to each of the virtual cells.

On the CP, it is simultaneously sent to the terminal.

In the above solution, the determining, according to the current radio link status, the CP from the virtual cell to which the terminal belongs is:

The CP is determined from the virtual cells to which the terminal belongs according to the signal strength of the terminal on the CPs in the virtual cell.

In the above solution, the determining, according to the signal strength of each terminal of the terminal in the virtual cell, the CP is determined from the virtual cell to which the terminal belongs, as follows:

Comparing the currently measured signal strength of each terminal on each CP in the virtual cell with a set threshold, and determining a CP in the virtual cell whose signal strength exceeds the threshold is determined as the current terminal Activate the CP collection.

In the above solution, the base station is further configured to compare, by using the periodically measured, the signal strength of each terminal of the terminal in the virtual cell with the set threshold, and adopting a signal strength exceeding a threshold. The CP in the virtual cell updates the current active CP set of the terminal.

The method and system for eliminating inter-cell interference provided by the present invention, configuring one or more virtual cells on a base station, and configuring two or more physical cells for each virtual cell, each physical cell as a CP, and configured in each virtual cell All the CPs share the common resources of the cell level; when performing the service, the base station determines the CP from the virtual cell to which the terminal belongs according to the current radio link status, and performs transmission and reception of the service data through the determined CP, and thus, It can effectively eliminate inter-cell interference and improve the throughput of the LTE system.

In the present invention, by combining a plurality of CPs into one virtual cell, the coverage of the extended virtual cell is several times larger than that of the conventional physical cell, thereby reducing the switching rate and the dropped call rate of the edge users, thereby effectively The problem of the handover rate and the dropped call rate caused by the limited coverage of the cell in the wireless mobile communication system is solved.

In addition, the technical solution provided by the present invention does not rely on communication with a base station, nor does it depend on a neighboring area. The use of the radio resource is completely transparent to the terminal and is only implemented on the base station side. Therefore, the solution provided by the present invention can be compatible with the current LTE system design, and supports the normal cell hybrid group in the LTE system that does not use the technical solution of the present invention. network. DRAWINGS

1 is a schematic flowchart of a method for eliminating inter-cell interference according to the present invention;

2 is a schematic flowchart of a method for eliminating inter-cell interference according to an embodiment of the present invention;

FIG. 3 is a schematic structural diagram of a system for eliminating inter-cell interference according to the present invention. detailed description

The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

The method for eliminating inter-cell interference, as shown in FIG. 1 , includes the following steps: Step 100: Configure one or more virtual cells on a base station, and configure two or more physical cells for each virtual cell, and each physical cell serves as one The CP, and all the cells in each virtual cell are configured to share the cell-level common resources, and then step 101 is performed;

Step 101: When performing the service, the base station determines the CP from the virtual cell to which the terminal belongs according to the current radio link status, and performs service data transmission and reception through the determined CP.

Here, the base station determines the CP from the virtual cell to which the terminal belongs according to the current radio link status, specifically:

The base station determines the CP from the virtual cell to which the terminal belongs according to the signal strength of the terminal on the CP in the virtual cell.

More specifically, comparing the currently measured signal strength of each terminal on each CP in the virtual cell with a set threshold, and the virtual cell in which the signal strength exceeds the threshold

The CP is determined to be the current active CP set of the terminal.

Here, the number of CPs determined from the virtual cell to which the terminal belongs may be one or more, in other words, in actual application, the CP determined from the virtual cell to which the terminal belongs The number can be more than one. Correspondingly, the number of CPs in the current active CP set of the terminal may be more than one.

The sending and receiving of the service data by using the determined CP is specifically:

The base station sends the service data to each of the determined CPs in the activated CP set of the terminal, and simultaneously sends the data to the terminal;

In actual application, when two or more virtual cells are configured, each terminal belongs to only one of the virtual cells. That is, when determining the CP, the base station determines only the corresponding CP from the virtual cell to which the terminal belongs. The corresponding CP is not determined from all configured virtual cells.

The method may further comprise:

The base station periodically measures the signal strength of the CPs on the CPs in the virtual cell, and compares the measured signal strengths of the terminals on the CPs in the virtual cell with the set thresholds, and adopts The CP in the virtual cell whose signal strength exceeds the threshold increases the current active CP set of the terminal.

The method may further comprise:

When it is required to transmit control channel information, and/or cell common information, the base station transmits control channel information, and/or cell common information to each CP in the virtual cell, and simultaneously transmits the same to the terminal.

The common information of the cell includes: a cell ID, a primary and secondary synchronization signal, a frequency hopping sequence, and a scrambling sequence.

The present invention will be further described in detail below with reference to the embodiments.

The method for eliminating inter-cell interference in this embodiment, as shown in FIG. 2, includes the following steps: Step 200: The OMC (Operation Maintenance Center) configures one or more virtual cells on the base station, and configures two virtual cells for each virtual cell. More than one physical community, Each physical cell acts as a CP, and all cells in each virtual cell are configured to share cell-level common resources;

Here, when configuring a virtual cell, more than one virtual cell may be configured according to the network requirement, or may be mixed with a normal cell, and the configured virtual cell may be reflected on the bottom layer of the base station, but is invisible to the upper layer service and the terminal. That is, for high-level services and terminals, the virtual cell is treated equivalently to the normal cell.

The normal cell refers to: a physically existing physical cell; the specific process of configuring the virtual cell may adopt the prior art.

When two or more physical cells are configured for each virtual cell, the two or more physical cells are: two or more physical cells that are geographically connected; where the physical cell is a cell covered by the base station. A specific processing procedure for configuring two or more physical cells for each virtual cell is a technical means used by those skilled in the art, and details are not described herein again.

The configuration of the common cell-level common resource on all the CPs in each virtual cell means that the common resource of the cell level configured by each CP in each virtual cell is the same, and thus, for the terminal, only the base station is received through one cell. The information sent, in other words, each in each virtual cell

The radio ends corresponding to the CPs send the same cell-level common resources to the terminal. The cell-level public resources include: a cell ID, a primary and secondary synchronization signal, a frequency hopping sequence, and a scrambling sequence.

Step 201: The base station periodically updates the activated CP set of the terminal according to the acquired signal strength of the terminal on each CP in the virtual cell.

Specifically, the base station periodically compares the measured signal strength of each terminal on each CP in the virtual cell with a set threshold, and forms a CP in the virtual cell whose signal strength exceeds the threshold, and forms the current The active CP collection of the terminal.

The specific processing procedure for the base station to measure the signal strength of the terminal on each CP in the virtual cell is prior art.

Step 202: When the base station needs to send information to the terminal, according to different types of information, The same CP sends information to the terminal;

Specifically, when the information is the control channel information, and/or the cell common information, the base station sends the control channel information, and/or the cell common information to each CP in the virtual cell, and simultaneously sends the information to the terminal; When the channel information is transmitted, the base station sends the traffic channel information to each CP in the currently activated CP set corresponding to the terminal, and simultaneously sends the information to the terminal. Here, the traffic channel information refers to service data.

Here, after receiving the information, the terminal combines and demodulates the received information on each CP; the specific processing procedure of the terminal performing the combined demodulation is the same as the prior art, and details are not described herein again.

Step 203: When the terminal needs to send information, send information to the base station through each CP in the virtual cell.

Here, since the terminal does not see each CP in the virtual cell, in this step, the actual operation of the terminal is completely the same as the specific processing procedure of transmitting information to the base station through the normal cell.

The information refers to service data.

Step 204: The base station receives the information sent by the terminal on each CP in the virtual cell, and combines and demodulates the information on each CP in the currently activated CP set corresponding to the terminal.

Here, the signals received on each CP in the virtual cell are the same.

The specific processing of combining and demodulating the information on each CP in the currently activated CP set corresponding to the terminal may adopt the prior art.

As can be seen from the above description, the technical solution provided by the present invention is actually a macro diversity technology, and the macro diversity technology plays a very important role in the third generation mobile communication era. In the existing LTE system, the gain is obtained only by link adaptation and fast retransmission, and the technology that requires network architecture support such as macro diversity is abandoned. In an Orthogonal Frequency Division Multiplexing (OFDM) system, soft combining can be implemented by radio frequency combining in which the signal arrives at the terminal antenna at the time of the cyclic prefix window. This combination does not require any operation of the terminal. . In the present invention, one or more virtual cells are configured in a network range, and each virtual cell is composed of a plurality of adjacent traditional physical cells, each physical cell is a CP, and multiple physical cells are bound. Forming a virtual cell equivalent to a traditional cell, each physical cell is one

CP. The cell-level common resources are shared among all the CPs in the virtual cell, that is, the cell-level public resources need to be sent out on the radio terminals of the CPs of the virtual cell. According to the corresponding wireless air interface condition of the terminal, that is, according to the state of the wireless link, the base station periodically updates and maintains the activated CP set of each terminal, and then completes the transmission and reception of the service data through the activated CP set of each terminal. In other words, the base station determines which CPs in the virtual cell to transmit and receive with the service data between the terminals based on the state of the radio link.

The technical solution provided by the present invention, by combining multiple CPs into one virtual cell, the coverage of the extended virtual cell is several times larger than that of the traditional physical cell, thus effectively eliminating inter-cell interference and improving the LTE system. The throughput, thereby reducing the switching rate and dropped call rate of the edge users, solves the problem caused by the limited coverage of the cell in the wireless mobile communication system. In the present invention, a channel gain similar to macro diversity is obtained without requiring a "central node" such as a Radio Network Controller (RNC) to perform control. The method provided by the present invention can be compatible with current system design, and supports hybrid networking of normal cells in an LTE system that does not use the technical solution of the present invention.

In order to achieve the foregoing solution, the present invention further provides a system for eliminating inter-cell interference. As shown in FIG. 3, the system includes: a configuration unit 31 and a base station 32;

The configuration unit 31 is configured to configure one or more virtual cells on the base station 32, and configure two or more physical cells for each virtual cell, each physical cell as one CP, and configure all CPs in each virtual cell to share the cell level. Public resource;

The base station 32 is configured to determine, according to the current radio link status, the CP from the virtual cell to which the terminal belongs, and perform the sending and receiving of the service data by using the determined CP.

The configuration unit 31 may specifically be an OMC. The base station 32 is further configured to: when the control channel information and/or the cell common information needs to be sent, send the control channel information, and/or the cell common information to each CP in the virtual cell, and send the same to the terminal. .

Here, it should be noted that the specific processing procedure of the base station in the system of the present invention has been reviewed above and will not be described again.

The above is only the preferred embodiment of the present invention and is not intended to limit the scope of the present invention.

Claims

Claim

A method for eliminating inter-cell interference, the method comprising:

Configuring one or more virtual cells on the base station, and configuring two or more physical cells for each virtual cell, each physical cell serving as a cell segment (CP), and configuring all CPs in each virtual cell to share cell-level common resources. ;

The method according to claim 1, wherein the base station determines the CP from the virtual cell to which the terminal belongs according to the current wireless link status, which is:

The base station determines the CP from the virtual cell to which the terminal belongs according to the signal strength of each terminal of the terminal in the virtual cell obtained by the current measurement.

The method according to claim 2, wherein the base station determines a CP from a virtual cell to which the terminal belongs according to the signal strength of each terminal in the virtual cell obtained by the current measurement. For:

The method according to claim 3, wherein the method further comprises: the base station comparing, by the base station, the signal strength of each terminal of the terminal in the virtual cell with the set threshold value And updating the current active CP set of the terminal by using the CP in the virtual cell whose signal strength exceeds the threshold.

The method according to claim 3, wherein the sending and receiving of the service data by the determined CP is:

Sending, by the base station, the service data to each CP in the determined active CP set of the terminal, and simultaneously sending the data to the terminal; The base station combines and demodulates the service data sent by the terminal received on each CP in the current activated CP set of the terminal to obtain the service data sent by the terminal.

The method according to any one of claims 1 to 5, characterized in that the method further comprises:

A system for eliminating inter-cell interference, the system comprising: a configuration unit and a base station;

The system according to claim 7, wherein the base station is further configured to: when control channel information and/or cell common information needs to be sent, send control channel information and/or cell common information to Each CP in the virtual cell is simultaneously sent to the terminal.

The system according to claim 7 or 8, wherein the determining the CP from the virtual cell to which the terminal belongs according to the current wireless link status is:

The system according to claim 9, wherein the determining, according to the currently measured signal strength of each terminal on each CP in the virtual cell, determining a CP from the virtual cell to which the terminal belongs, :

The currently measured signal strength of the terminal on each CP in the virtual cell The set threshold is compared, and the CP in the virtual cell whose signal strength exceeds the threshold is determined as the current active CP set of the terminal.

The system according to claim 10, wherein the base station is further configured to perform, by using the periodically measured, the signal strength of the terminal on each CP in the virtual cell, and the set threshold value. Comparing, and using the CP in the virtual cell whose signal strength exceeds the threshold, updating the current active CP set of the terminal.

The system according to claim 10, wherein the transmitting and receiving of the service data by the determined CP is:

Transmitting the service data to each of the determined CPs in the activated CP set of the terminal, and simultaneously transmitting the data to the terminal;

The service data sent by the terminal received on each CP in the currently activated CP set of the terminal is combined and demodulated to obtain service data sent by the terminal.