Method, apparatus and system for implementing multi-user virtual multiple-input multiple-output

• US 8,305,956 B2
• Filed: 08/07/2007
• Issued: 11/06/2012
• Est. Priority Date: 08/07/2006
• Status: Expired due to Fees

• Current Assignee: Interdigital Technology Corporation (InterDigital, Inc.)
• Original Assignee: Interdigital Technology Corporation (InterDigital, Inc.)
• Inventors: Olesen, Robert Lind, Grieco, Donald M., Pan, Kyle Jung-Lin
• Primary Examiner(s): Pham, Chi H.
• Assistant Examiner(s): MEW, KEVIN D
• Application Number:
  US11/834,923
• Publication Number:
  US 20080032746A1
• Time in Patent Office: 1,918 Days
• Field of Search: 370/206, 370/208, 370328-329, 370/335, 370338-339, 370342-344, 370400-401, 455/101, 455/422.1, 455/452.1, 455/562.1
• US Class Current: 370/328
• CPC Class Codes: H04B 7/0452 Multi-user MIMO systems
• CPC Class Codes: H04B 7/0617 for beam forming
• CPC Class Codes: H04B 7/0669 using different channel coding between antennas space-time coding H04L1/0618
• CPC Class Codes: H04B 7/0671 using different delays between antennas

Abstract

A method and system for implementing multi-user virtual multiple-input multiple-output (MIMO) techniques for wireless transmit/receive units (WTRUs) having one or more antennas are disclosed. The system includes a base station and at least one WTRU having at least two antennas. The number of antennas of the base station is not less than the number of antennas of any of the WTRUs. The base station generates a channel matrix for the WTRUs and processes received signals from the WTRUs based on a measurement of the channel matrix. The WTRUs may perform transmit precoding or eigen-beamforming using the channel matrix information. The WTRUs may also perform transmit diversity.

Claims

1. In a wireless communication system including a base station and a plurality of wireless transmit/receive units (WTRUs), the base station including a plurality of antennas grouped into base station antenna groups, and at least one of said WTRUs including at least two antennas, wherein the number of antennas of the base station is not less than the number of antennas of any of the WTRUs, a method for implementing multi-user virtual multiple-input multiple-output (MIMO), the method comprising:

the base station generating a multipath channel matrix between each WTRU and each base station antenna group, wherein the multipath channel matrix comprises channel coefficients for the antennas associated with each WTRU and the antennas associated with each base station antenna group of the base station;

the base station generating an effective channel matrix for channels between the base station and the WTRUs, wherein the effective channel matrix comprises the multipath channel matrices for each WTRU and is an effective MIMO channel for the multi-user virtual MIMO; and

the base station processing received signals from the WTRUs using the effective channel matrix.

2. The method of claim 1 wherein the WTRUs perform a transmit precoding using the effective channel matrix.

3. The method of claim 1 wherein the WTRUs perform eigen-beamforming using the effective channel matrix.

4. The method of claim 1 wherein the WTRUs perform transmit diversity.

5. The method of claim 4 wherein the WTRUs perform at least one of space time block coding (STBC), space frequency block coding (SFBC), and cyclic delay diversity (CDD).

6. The method of claim 1 wherein at least one of the WTRUs supports one spatial stream and the rest of the WTRUs support at least two spatial streams.

7. The method of claim 1 wherein the base station and the WTRUs implement single carrier frequency division multiple access (SC-FDMA).

8. The method of claim 1 wherein the base station and the WTRUs implement orthogonal frequency division multiple access (OFDMA).

9. The method of claim 1 wherein the base station and the WTRUs implement multi-carrier orthogonal frequency division multiple access (MC-OFDMA).

10. A wireless communication system for implementing multi-user virtual multiple-input multiple-output (MIMO), the system comprising:

a plurality of wireless transmit/receive units (WTRUs), at least one WTRU having at least two antennas; and

a base station comprising;

a plurality of antennas, the number of the base station antennas being not less than the number of antennas of any of the WTRUs and the plurality of antennas being grouped into base station antenna groups;

a channel estimator for generating a multipath channel matrix between each WTRU and each base station antenna group and an effective channel matrix for channels between the base station and the WTRUs based on the multipath channel matrices, wherein the effective channel matrix is an effective MIMO channel for the multi-user virtual MIMO, and wherein wherein the multipath channel matrix comprises channel coefficients for the antennas associated with each WTRU and the antennas associated with each base station antenna group; and

a receiver for processing signals from the WTRUs using the effective channel matrix.

11. The system of claim 10 wherein the WTRUs perform transmit precoding using the effective channel matrix.

12. The system of claim 10 wherein the WTRUs perform eigen-beamforming using the effective channel matrix.

13. The system of claim 10 wherein the WTRUs perform transmit diversity.

14. The system of claim 13 wherein the WTRUs perform at least one of space time block coding (STBC) and space frequency block coding (SFBC).

15. The system of claim 10 wherein at least one of the WTRUs supports one spatial stream and the rest of the WTRUs support at least two spatial streams.

16. The system of claim 10 wherein the base station and the WTRUs implement single carrier frequency division multiple access (SC-FDMA).

17. The system of claim 10 wherein the base station and the WTRUs implement orthogonal frequency division multiple access (OFDMA).

18. The system of claim 10 wherein the base station and the WTRUs implement multi-carrier orthogonal frequency division multiple access (MC-OFDMA).

19. The system of claim 10 wherein the WTRUs selectively transmit the signals using one of a single stream MIMO and a multi-stream MIMO.

20. A base station for implementing multi-user virtual multiple-input multiple-output (MIMO) for a plurality of wireless transmit/receive units (WTRUs), at least one WTRU having at least two antennas, the base station comprising:

a plurality of antennas, the number of the base station antennas being not less than the number of antennas of any of the WTRUs and the plurality of antennas being grouped into base station antenna groups;

a channel estimator for generating a multipath channel matrix between each WTRU and each base station antenna group and an effective channel matrix for channels between the base station and the WTRUs based on the multipath channel matrices, wherein the effective channel matrix is an effective MIMO channel for the multi-user virtual MIMO, and wherein wherein the multipath channel matrix comprises channel coefficients for the antennas associated with each WTRU and the antennas associated with each base station antenna group; and

a receiver for processing signals from the WTRUs using the effective channel matrix.

21. The base station of claim 20 wherein the receiver is configured to process the signals that are processed for transmit precoding by the WTRUs using the effective channel matrix.

22. The base station of claim 20 wherein the receiver is configured to process the signals that are processed for eigen-beamforming by the WTRUs using the effective channel matrix.

23. The base station of claim 20 wherein the receiver is configured to process the signals that are processed for transmit diversity by the WTRUs.

24. The base station of claim 23 wherein the receiver is configured to process the signals that are processed for at least one of space time block coding (STBC), space frequency block coding (SFBC), and cyclic delay diversity (CDD) by the WTRUs.

25. The base station of claim 20 wherein at least one of the WTRUs supports one spatial stream and the rest of the WTRUs support at least two spatial streams.

26. The base station of claim 20 wherein the base station implements single carrier frequency division multiple access (SC-FDMA).

27. The base station of claim 20 wherein the base station implements orthogonal frequency division multiple access (OFDMA).

28. The base station of claim 20 wherein the base station implements multi-carrier orthogonal frequency division multiple access (MC-OFDMA).