METHOD FOR REDUCING INTER-CELL INTERFERENCE

• US 20120108278A1
• Filed: 01/06/2012
• Published: 05/03/2012
• Est. Priority Date: 12/31/2007
• Status: Active Grant

• Current Assignee: LG Electronics, Inc. (LG Corporation)
• Original Assignee: LG Electronics, Inc. (LG Corporation)
• Inventors: Kim, Jae Wan, Lee, Wook Bong, Kim, Su Nam, Lim, Dong Guk, Ihm, Bin Chul
• Granted Patent: US 8,190,094 B2
• Time in Patent Office: Days
• US Class Current: 455/501
• CPC Class Codes: H04B 17/345 Interference values signal-to-interference ratio [SIR] or carrier-to-interference ratio [CIR] H04B17/336
• CPC Class Codes: H04B 7/024 Co-operative use of antennas of several sites, e.g. in co-ordinated multipoint or co-operative multiple-input multiple-output [MIMO] systems
• CPC Class Codes: H04B 7/026 Co-operative diversity, e.g. using fixed or mobile stations as relays
• CPC Class Codes: H04B 7/0413 MIMO systems
• CPC Class Codes: H04B 7/0417 Feedback systems
• CPC Class Codes: H04B 7/0452 Multi-user MIMO systems
• CPC Class Codes: H04B 7/0495 using overlapping sectors in the same base station to implement MIMO for antennas
• CPC Class Codes: H04B 7/0626 Channel coefficients, e.g. channel state information [CSI]
• CPC Class Codes: H04B 7/0632 Channel quality parameters, e.g. channel quality indicator [CQI]
• CPC Class Codes: H04B 7/0634 Antenna weights or vector/matrix coefficients
• CPC Class Codes: H04B 7/0639 Using selective indices, e.g. of a codebook, e.g. pre-distortion matrix index [PMI] or for beam selection
• CPC Class Codes: H04L 1/0026 Transmission of channel quality indication
• CPC Class Codes: H04L 25/03904 cooperative design, e.g. exchanging of codebook information between base stations
• CPC Class Codes: H04W 24/02 Arrangements for optimising operational condition
• CPC Class Codes: H04W 72/02 Selection of wireless resources by user or terminal

Abstract

A method for reducing inter-cell interference and a method for transmitting a signal by a collaborative MIMO scheme, in a communication system having a multi-cell environment are disclosed. An example of a method for transmitting, by a mobile station, precoding information in a collaborative MIMO communication system includes determining a precoding matrix set including precoding matrices of one more base stations including a serving base station, based on signal strength of the serving base station, and transmitting information about the precoding matrix set to the serving base station. A mobile station in an edge of a cell performs a collaborative MIMO mode or inter-cell interference mitigation mode using the information about the precoding matrix set collaboratively with neighboring base stations.

Claims

1. A mobile station in a multi-cell environment, the mobile station comprising:

a processor for calculating two or more first precoding matrix indexes in which interference generated in a specific frequency band by at least one neighboring base station is maximized and two or more second precoding matrix indexes in which the interference is minimized,

wherein the two or more the first or second precoding matrix indexes are transmitted to a serving base station together with corresponding base station identifier information.

2. The mobile station according to claim 1, wherein the first precoding matrix index is for restricting a use of a precoding matrix corresponding to the first precoding matrix index by the at least one neighboring base station.

3. The mobile station according to claim 1, wherein the second precoding matrix index is for recommending a use of a precoding matrix corresponding to the second precoding matrix index by the at least one neighboring base station.

4. The mobile station according to claim 1, wherein interference amount information caused by the at least one neighboring base station is transmitted to the serving base station, with the two or more first or second precoding matrix indexes.

5. The mobile station according to claim 4, wherein the interference amount information includes at least one of Signal to Interference plus Noise Ratio (SINR) and Normalized Interference Power (NIP).

6. The mobile station according to claim 1, wherein the processor calculates the two or more of the first precoding matrix indexes or the second precoding matrix indexes in order of increasing or decreasing the interference based on the measured channel.

7. The mobile station according to claim 1, wherein the two or more first or second precoding matrix indexes is transferred to a neighboring base station corresponding to the base station identifier information via the serving base station.

8. A base station in a multi-cell environment, the base station comprising:

a processor for processing two or more first precoding matrix indexes in which interference generated in a specific frequency band by at least one neighboring base station is maximized and two or more second precoding matrix indexes in which the interference is minimized, which are received from a mobile station together with corresponding base station identifier information;

, and

wherein the two or more first or second precoding matrix indexes are transferred to the at least one neighboring base station according to the base station identifier information.

9. The base station according to claim 8, wherein the first precoding matrix index is for restricting a use of a precoding matrix corresponding to the first precoding matrix index by the at least one neighboring base station.

10. The base station according to claim 8, wherein the second precoding matrix index is for recommending a use of a precoding matrix corresponding to the second precoding matrix index by the at least one neighboring base station.

11. The base station according to claim 8, wherein interference amount information caused by the at least one neighboring base station is received from the mobile station, with the two or more first or second precoding matrix indexes.

12. The base station according to claim 11, wherein the interference amount information includes at least one of Signal to Interference plus Noise Ratio (SINR) and Normalized Interference Power (NIP).

13. The base station according to claim 8, wherein the two or more of the first precoding matrix indexes or the second precoding matrix indexes are calculated in order of increasing or decreasing the interference based on the measured channel, by the mobile station.