Method for transmitting and receiving signals using collaborative MIMO scheme

• US 20090207822A1
• Filed: 12/29/2008
• Published: 08/20/2009
• 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, Lim, Dong Guk, Ihm, Bin Chul, Kim, Su Nam, Lee, Wook Bong
• Granted Patent: US 8,179,819 B2
• Time in Patent Office: Days
• US Class Current: 370/338
• 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 method for a mobile station to receive a signal using a collaborative multiple-input multiple-output (Co-MIMO) scheme, the method comprising:

measuring a channel from a serving base station and collaborative base stations including at least one neighboring base station, wherein the collaborative base stations perform the collaborative MIMO scheme together with the serving base station;

determining precoding matrix indexes for each of the collaborative base stations and reporting the precoding matrix indexes to the serving base station; and

receiving a same signal or independent signals from the collaborative base stations.

2. The method according to claim 1, wherein the precoding matrix indexes for each of the collaborative base stations are selected based on a predetermined codebook in a system.

3. The method according to claim 1, wherein the precoding matrix indexes for each of the collaborative base stations are determined by selecting precoding matrix indexes in which a multi-cell diversity gain or a multi-cell multiplexing gain is maximally obtained, when the mobile station collaboratively receives the same signal or independent signals from each of the collaborative base stations.

4. The method according to claim 1, wherein the precoding matrix indexes for each of the collaborative base stations are determined by sequentially selecting a prescribed number of precoding matrix indexes in which a multi-cell diversity gain or a multi-cell multiplexing gain is maximally obtained, when the mobile station collaboratively receives the same signal or independent signals from each of the collaborative base stations.

5. The method according to claim 1, wherein the collaborative base stations share resource allocation information for the mobile station and transmit the same signal or independent signals to the mobile station using a common resource.

6. The method according to claim 1, wherein the precoding matrix indexes reported to the serving base station are respectively transmitted to the collaborative base stations from the serving base station via an inter-network interface.

7. The method according to claim 1, wherein the mobile station receives the same signal from the collaborative base stations when the collaborative base stations are operated in a multi-cell diversity mode.

8. The method according to claim 1, wherein the mobile station receives the independent signals from the collaborative base stations when the collaborative base stations are operated in a multi-cell multiplexing mode.

9. A method for a specific base station to transmit a signal together using a collaborative multiple-input multiple-output (Co-MIMO) scheme, the method comprising:

receiving, from a mobile station that receives a signal using the collaborative MIMO scheme, precoding matrix indexes for the specific base station and collaborative base stations including at least one neighboring base station, wherein the collaborative base stations performing the collaborative MIMO scheme together with the specific base station;

transmitting the precoding matrix indexes for each of the collaborative base stations to the at least one neighboring base station through an inter-network interface; and

transmitting the same signal or independent signals to the mobile station together with the at least one neighboring base station.

10. The method according to claim 9, wherein the precoding matrix indexes for each of the collaborative base stations are selected based on a predetermined codebook in a system.

11. The method according to claim 9, wherein the precoding matrix indexes for each of the collaborative base stations are determined by selecting precoding matrix indexes in which a multi-cell diversity gain or multi-cell multiplexing gain is maximally obtained, when the mobile station collaboratively receives the same signal or independent signals from the collaborative base stations.

12. The method according to claim 9, wherein the precoding matrix indexes for each of the collaborative base stations are determined by sequentially selecting a prescribed number of precoding matrix indexes in which a multi-cell diversity gain or a multi-cell multiplexing gain is maximally obtained, when the mobile station collaboratively receives the same signal or independent signals from the collaborative base stations.

13. The method according to claim 9, wherein the collaborative base stations share resource allocation information for the mobile station and transmit the same signal or independent signals to the mobile station using a common resource.

14. The method according to claim 9, wherein the specific base station transmits the same signal to the mobile station together with the at least one neighboring base station, when the collaborative base stations are operated in a multi-cell diversity mode.

15. The method according to claim 9, wherein the specific base station transmits the independent signals to the mobile station together with the at least one neighboring base station, when the collaborative base stations are operated in a multi-cell multiplexing mode.