Spatial spreading with space-time and space-frequency transmit diversity schemes for a wireless communication system

• US 20060067421A1
• Filed: 09/01/2005
• Published: 03/30/2006
• Est. Priority Date: 09/03/2004
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Walton, Jay Rodney, Howard, Steven J., Ketchum, John W., Wallace, Mark S.
• Granted Patent: US 7,894,548 B2
• Time in Patent Office: Days
• US Class Current: 375/267
• CPC Class Codes: H04B 7/0615 of weighted versions of same signal
• CPC Class Codes: H04B 7/0617 for beam forming
• CPC Class Codes: H04B 7/0667 of delayed versions of same signal using space-time coding H04L1/0618
• CPC Class Codes: H04B 7/0678 using different spreading codes between antennas code allocation H04J13/16
• CPC Class Codes: H04B 7/068 using space frequency diversity space-frequency coding H04L1/0606
• CPC Class Codes: H04B 7/0689 using different transmission schemes, at least one of them being a diversity transmission scheme
• CPC Class Codes: H04B 7/0697 using spatial multiplexing
• CPC Class Codes: H04B 7/12 Frequency diversity
• CPC Class Codes: H04J 13/004 Orthogonal
• CPC Class Codes: H04L 1/0041 Arrangements at the transmitter end
• CPC Class Codes: H04L 1/0606 Space-frequency coding
• CPC Class Codes: H04L 1/0625 Transmitter arrangements
• CPC Class Codes: H04L 1/0637 Properties of the code
• CPC Class Codes: H04L 1/0668 Orthogonal systems, e.g. using Alamouti codes
• CPC Class Codes: H04L 27/2626 Arrangements specific to the transmitter only
• CPC Class Codes: H04L 5/0023 Time-frequency-space

Abstract

Techniques for transmitting data using a combination of transmit diversity schemes are described. These transmit diversity schemes include spatial spreading, continuous beamforming, cyclic delay diversity, space-time transmit diversity (STTD), space-frequency transmit diversity (SFTD), and orthogonal transmit diversity (OTD). A transmitting entity processes one or more (N_D) data symbol streams based on a transmit diversity scheme (e.g., STTD, SFTD, or OTD) to generate multiple (N_C) coded symbol streams. Each data symbol stream may be sent as a single coded symbol stream or as multiple (e.g., two) coded symbol streams using STTD, SFTD, or OTD. The transmitting entity may perform spatial spreading on the N_C coded symbol streams with different matrices to generate multiple (N_T) transmit symbol streams for transmission from N_T antennas. Additionally or alternatively, the transmitting entity may perform continuous beamforming on the N_T transmit symbol streams in either the time domain or the frequency domain.

Claims

1. An apparatus comprising:

at least one processor configured to process data symbols based on a transmit diversity scheme to generate coded symbols, and to perform spatial processing on the coded symbols to generate transmit symbols for transmission via a plurality of antennas; and

a memory coupled to the at least one processor.

2. The apparatus of claim 1, wherein the at least one processor is configured to perform spatial spreading with a plurality of matrices and to use different matrices for different frequency subbands, different time intervals, or both.

3. The apparatus of claim 1, wherein the at least one processor is configured to perform beamforming with a plurality of matrices and to use different matrices for different frequency subbands.

4. The apparatus of claim 1, wherein the at least one processor is configured to process the data symbols based on a space-time transmit diversity (STTD) scheme to generate the coded symbols.

5. The apparatus of claim 1, wherein the at least one processor is configured to process the data symbols based on a space-frequency transmit diversity (SFTD) scheme to generate the coded symbols.

6. The apparatus of claim 1, wherein the at least one processor is configured to process the data symbols based on an orthogonal transmit diversity (OTD) scheme to generate the coded symbols.

7. The apparatus of claim 1, wherein the at least one processor is configured to obtain at least two data symbols to be sent on a frequency subband in two symbol periods, to process the at least two data symbols based on the transmit diversity scheme to generate two sets of coded symbols, and to provide the two sets of coded symbols for transmission on the frequency subband in two symbol periods.

8. The apparatus of claim 1, wherein the at least one processor is configured to obtain at least two data symbols to be sent on two frequency subbands in a symbol period, to process the at least two data symbols based on the transmit diversity scheme to generate two sets of coded symbols, and to provide the two sets of coded symbols for transmission on the two frequency subbands in the symbol period.

9. The apparatus of claim 1, wherein the at least one processor is configured to perform orthogonal frequency division multiplexing (OFDM) modulation on the transmit symbols for each antenna to generate transmission symbols for the antenna.

10. The apparatus of claim 1, wherein the at least one processor is configured to perform single-carrier frequency division multiple access (SC-FDMA) modulation on the transmit symbols for each antenna to generate transmission symbols for the antenna.

11. The apparatus of claim 1, wherein the at least one processor is configured to apply different cyclic delays for the plurality of antennas.

12. The apparatus of claim 1, wherein the at least one processor is configured to generate transmission symbols for the plurality of antennas based on the transmit symbols, and to cyclically delay the transmission symbols for the plurality of antennas by different non-negative integer numbers of samples.

13. A method comprising:

processing data symbols based on a transmit diversity scheme to generate coded symbols; and

performing spatial processing on the coded symbols to generate transmit symbols for transmission via a plurality of antennas.

14. The method of claim 13, wherein the processing the data symbols based on the transmit diversity scheme comprises

processing the data symbols based on a space-time transmit diversity (STTD) scheme, a space-frequency transmit diversity (SFTD) scheme, or an orthogonal transmit diversity (OTD) scheme to generate the coded symbols.

15. The method of claim 13, wherein the performing spatial processing on the coded symbols comprises

performing spatial spreading with a plurality of matrices, and

using different matrices for different frequency subbands, different time intervals, or both.

16. The method of claim 13, further comprising:

applying different cyclic delays for the plurality of antennas.

17. An apparatus comprising:

means for processing data symbols based on a transmit diversity scheme to generate coded symbols; and

means for performing spatial processing on the coded symbols to generate transmit symbols for transmission via a plurality of antennas.

18. The apparatus of claim 17, wherein the means for processing the data symbols based on the transmit diversity scheme comprises

means for processing the data symbols based on a space-time transmit diversity (STTD) scheme, a space-frequency transmit diversity (SFTD) scheme, or an orthogonal transmit diversity (OTD) scheme to generate the coded symbols.

19. The apparatus of claim 17, wherein the means for performing spatial processing on the coded symbols comprises

means for performing spatial spreading a the plurality of matrices, and

means for using different matrices for different frequency subbands, different time intervals, or both.

20. The apparatus of claim 17, further comprising:

means for applying different cyclic delays for the plurality of antennas.

21. An apparatus comprising:

at least one processor configured to process at least one data symbol stream based on a transmit diversity scheme to generate at least two coded symbol streams, and to perform spatial processing on the at least two coded symbol streams to generate a plurality of transmit symbol steams for transmission via a plurality of antennas; and

a memory coupled to the at least one processor.

22. The apparatus of claim 21, wherein the at least one processor is configured to process the at least one data symbol stream based on a space-time transmit diversity (STTD) scheme, a space-frequency transmit diversity (SFTD) scheme, or an orthogonal transmit diversity (OTD) scheme to generate the at least two coded symbol streams.

23. The apparatus of claim 21, wherein the at least one processor is configured to perform spatial spreading with a plurality of matrices and to use different matrices for different frequency subbands, different time intervals, or both.

24. The apparatus of claim 21, wherein the at least one processor is configured to generate at least one additional data symbol stream to be sent without the transmit diversity scheme, and to perform spatial processing on the at least two coded symbol streams and the at least one additional data symbol stream with the plurality of matrices to generate the plurality of transmit symbol steams.

25. The apparatus of claim 24, wherein the at least one processor is configured to scale the at least two coded symbol streams with at least two gains selected for the at least two coded symbol streams, and to scale the at least one additional data symbol stream with at least one gain selected for the at least one additional data symbol stream.

26. The apparatus of claim 21, wherein the at least one processor is configured to process at least one data stream based on at least one coding and modulation scheme to generate the at least one data symbol stream.

27. A method comprising:

processing at least one data symbol stream based on a transmit diversity scheme to generate at least two coded symbol streams; and

performing spatial processing on the at least two coded symbol streams to generate a plurality of transmit symbol steams for transmission via a plurality of antennas.

28. The method of claim 27, wherein the processing the at least one data symbol stream based on the transmit diversity scheme comprises

processing the at least one data symbol stream based on a space-time transmit diversity (STTD) scheme, a space-frequency transmit diversity (SFTD) scheme, or an orthogonal transmit diversity (OTD) scheme to generate the at least two coded symbol streams.

29. The method of claim 27, wherein the performing spatial processing on the at least two coded symbol streams comprises

performing spatial spreading on the at least two coded symbol streams with a plurality of matrices, and

using different matrices for different frequency subbands, different time intervals, or both.

30. An apparatus comprising:

means for processing at least one data symbol stream based on a transmit diversity scheme to generate at least two coded symbol streams; and

means for performing spatial processing on the at least two coded symbol streams to generate a plurality of transmit symbol steams for transmission via a plurality of antennas.

31. The apparatus of claim 30, wherein the means for processing the at least one data symbol stream based on the transmit diversity scheme comprises

means for processing the at least one data symbol stream based on a space-time transmit diversity (STTD) scheme, a space-frequency transmit diversity (SFTD) scheme, or an orthogonal transmit diversity (OTD) scheme to generate the at least two coded symbol streams.

32. The apparatus of claim 30, wherein the means for performing spatial processing on the at least two coded symbol streams comprises

means for performing spatial spreading on the at least two coded symbol streams with a plurality of matrices, and

means for using different matrices for different frequency subbands, different time intervals, or both.