High data rate closed loop mimo scheme combining transmit diversity and data multiplexing

• US 20030139139A1
• Filed: 11/21/2002
• Published: 07/24/2003
• Est. Priority Date: 11/21/2001
• Status: Active Grant

• Current Assignee: Intel Corporation
• Original Assignee: Texas Instruments, Inc.
• Inventors: Onggosanusi, Eko N., Dabak, Anand G., Schmidl, Timothy M.
• Granted Patent: US 7,181,167 B2
• Time in Patent Office: Days
• US Class Current: 455/63.1
• CPC Class Codes: H04B 7/0632 Channel quality parameters, e.g. channel quality indicator [CQI]
• CPC Class Codes: H04B 7/0854 using error minimizing algorithms, e.g. minimum mean squared error [MMSE], "cross-correlation" or matrix inversion
• CPC Class Codes: H04B 7/0857 using maximum ratio combining techniques, e.g. signal-to- interference ratio [SIR], received signal strenght indication [RSS]

Abstract

Closed loop multiple-antenna wireless communications system with antenna weights determined by maximizing a composite channel signal-to-interference-plus-noise ratio minimum. Multiplexed symbol streams over subsets of antennas enhance throughput.

Claims

1. A method of transmission, comprising:

(a) providing P transmit antennas where P is an integer greater than or equal to 3;

(b) providing estimates for communication channels from said P antennas to Q receive antenna(s) where Q is a positive integer;

(c) providing M symbol streams to transmit from said P antennas through said communication channels where M is an integer greater than or equal to 2;

(d) providing weights for said P antennas, said weights multiplying said symbols.

2. The method of claim 1, wherein:

(a) said providing weights of step (d) of claim 1 includes maximizing a minimum signal-to-interference-plus-noise ratio of said symbol streams after detection.

3. The method of claim 2, wherein:

(a) said detection of claim 2 is selected from the group consisting of linear zero-forcing, linear minimum mean square error, iterative zero-forcing, and iterative minimum mean square error.

4. The method of claim 2, wherein:

(a) said detection of claim 2 is maximum likelihood detector with SER selection criterion.

5. The method of claim 1, wherein:

(a) said weights of step (d) of claim 1 correspond to a diagonal M×

M block matrix of (P/M)×

1 blocks where each (P/M)×

1 block corresponds to weights for a symbol stream.

6. The method of claim 1, wherein:

(a) said weights of step (d) of claim 1 correspond to a (P/M)×

1 block matrix of M×

M blocks where each M×

M block is an M×

M unitary matrix.

7. The method of claim 1, wherein:

(a) said providing channel estimates of step (b) of claim 1 is by reception from said receiver in said channel.

8. The method of claim 1, wherein:

(a) said providing channel estimates of step (b) of claim 1 is by reception of channel information from said receiver.

9. The method of claim 1, wherein:

(a) said channel estimates of step (b) of claim 1 are updated; and

(b) said weights of step (d) of claim 1 are updated in response to said channel estimates update.

10. The method of claim 1, wherein:

(a) said integer Q is greater than or equal to said integer P.

11. The method of claim 1, wherein:

(a) said communication channels include multipath interference; and

(b) said detection accounts for said multipath interference.

Maximum likelihood+SER selection criterion.

12. The method of claim 11, wherein:

(a) said detection of step (d) of claim 1 is selected from the group consisting of linear zero-forcing, linear minimum mean square error, iterative zero-forcing, and iterative minimum mean square error.

13. The method of claim 1, wherein:

(a) said communication channel is a wideband or CDMA channel with multiple users.

14. The method of claim 1, wherein:

(a) said communication channel is a wideband or CDMA channel with a single user with multiple codes.

15. The method of claim 1, wherein:

(a) said communication channel is a narrowband or TDMA channel.

16. The method of claim 1, wherein:

(a) said communication channel is an OFDM channel.

17. A transmitter, comprising:

(a) P transmit antennas where P is an integer which is a multiple of an integer M where M is greater than 1;

(b) M data stream inputs coupled to said P antennas by PM weights;

said weights determined from both (i) information of communication channels from said P antennas to Q receive antenna(s) where Q is a positive integer, and a detection method for said M data streams at said Q antenna(s).

18. The transmitter of claim 17, wherein:

(a) said weights are all 0 except for M sets, each set of size P/M, and each of said M sets couples one of said data streams to a set of P/M antennas.

19. The transmitter of claim 17, wherein:

(a) said weights are partitioned into P/M sets, each set forming an M×

M unitary transformation of symbols at said M data stream inputs, and each of said P/M sets couples said M data streams inputs to a corresponding set of M antennas.

20. The transmitter of claim 17, wherein:

(a) said weights are determined outside of said transmitter and received by said transmitter from said signals from said Q antenna(s).

21. A receiver, comprising:

(a) Q antenna(s) where Q is a positive integer;

(b) a detector coupled to said Q antenna(s), said detector adapted to detect signals from P transmit antennas where P is an integer greater than or equal to 3 and with weights applied to said P antennas.

22. The receiver of claim 21, wherein:

(a) said weights combine symbols from M data streams and are determined from both (i) information of communication channels from said P antennas to said Q receive antenna(s) plus (ii) a detection method of said detector.

23. The receiver of claim 21, wherein:

(a) said detection method is maximum likelihood with SER selection criterion.

24. The receiver of claim 21, wherein:

(a) said detection method is selected from the group consisting of linear zero-forcing, linear minimum mean square error, iterative zero-forcing, and iterative minimum mean square error; and

(b) said weights determination includes maximization of minimum signal-to-interference-plus-noise ratio.