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

• US 9,264,116 B2
• Filed: 09/27/2012
• Issued: 02/16/2016
• Est. Priority Date: 08/07/2006
• Status: Expired due to Fees

• Current Assignee: InterDigital Patent Holdings, Inc. (InterDigital, Inc.)
• Original Assignee: InterDigital Patent Holdings, Inc. (InterDigital, Inc.)
• Inventors: Olesen, Robert L, Grieco, Donald M, Pan, Kyle Jung-Lin
• Primary Examiner(s): Mew, Kevin
• Application Number:
  US13/628,950
• Publication Number:
  US 20130022006A1
• Time in Patent Office: 1,237 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: 1/1
• 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, at least one of said WTRUs including at least two antennas, and the number of antennas of the base station being equal to or greater 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:

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

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 of the WTRUS and is an effective MIMO channel for the multi-user virtual MIMO; and

processing received signals from the WTRUs using the effective channel matrix, wherein a linear minimum mean square error is configured to be used to recover at least a portion of data in the received signals being processed.

2. The method of claim 1 wherein a transmit precoding is configured to be performed using the effective channel matrix.

3. The method of claim 1 wherein eigen-beamforming is configured to be performed using the effective channel matrix.

4. The method of claim 1 wherein transmit diversity is configured to be performed.

5. The method of claim 4 wherein at least one of space time block coding (STBC), space frequency block coding (SFBC), and cyclic delay diversity (CDD) is configured to be performed.

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 equal to or greater 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 of the WTRUs and each of the base station antenna groups 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 the multipath channel matrix comprises channel coefficients for the antennas associated with each of the WTRUs and the antennas associated with each of the base station antenna groups; and

a receiver for processing signals transmitted from the WTRUs using the effective channel matrix, wherein a linear minimum mean square error is configured to be used to recover at least a portion of data in the signals being processed.

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

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

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

14. The system of claim 13 wherein the WTRUs are configured to 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 equal to or greater 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 of the WTRUs and each of the base station antenna groups 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 the multipath channel matrix comprises channel coefficients for the antennas associated with each of the WTRUs and the antennas associated with each of the base station antenna groups; and

a receiver for processing signals transmitted from the WTRUs using the effective channel matrix, wherein a linear minimum mean square error is configured to be used to recover at least a portion of data in the signals being processed.

21. The base station of claim 20 wherein the receiver is configured to process the signals that are processed for transmit precoding 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 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.

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).

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).