TRANSMIT DIVERSITY PROCESSING FOR A MULTI-ANTENNA COMMUNICATION SYSTEM

• US 20100208841A1
• Filed: 06/24/2009
• Published: 08/19/2010
• Est. Priority Date: 10/25/2002
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Howard, Steven J., Ketchum, John W., Walton, J. Rodney, Wallace, Mark S.
• Granted Patent: US 8,873,365 B2
• Time in Patent Office: Days
• US Class Current: 375/295
• CPC Class Codes: H04B 7/0669 using different channel coding between antennas space-time coding H04L1/0618
• CPC Class Codes: H04B 7/0697 using spatial multiplexing
• 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: H04L 1/0003 by switching between different modulation schemes
• CPC Class Codes: H04L 1/0009 by adapting the channel coding H04L1/1812 takes precedence
• CPC Class Codes: H04L 1/0017 where the mode-switching is based on Quality of Service requirement
• CPC Class Codes: H04L 1/0059 Convolutional codes
• CPC Class Codes: H04L 1/0061 Error detection codes
• CPC Class Codes: H04L 1/0069 Puncturing patterns
• CPC Class Codes: H04L 1/0071 Use of interleaving interleaving per se H03M13/27
• CPC Class Codes: H04L 1/0618 Space-time coding
• CPC Class Codes: H04L 1/08 by repeating transmission, e.g. Verdan system H04L1/1858 and H04L1/189 take precedence
• CPC Class Codes: H04L 1/16 in which the return channel carries supervisory signals, e.g. repetition request signals
• CPC Class Codes: H04L 2001/0093 Point-to-multipoint
• CPC Class Codes: H04L 25/0224 using sounding signals
• CPC Class Codes: H04L 25/0226 sounding signals per se
• CPC Class Codes: H04L 25/0242 using matrix methods
• CPC Class Codes: H04L 25/03343 Arrangements at the transmitter end
• CPC Class Codes: H04L 27/2601 Multicarrier modulation systems
• CPC Class Codes: H04L 27/2602 Signal structure
• CPC Class Codes: H04L 27/261 : Details of reference signals
• CPC Class Codes: H04L 27/2647 : Arrangements specific to the receiver only equalisation H04L27/01
• CPC Class Codes: H04W 28/20 : Negotiating bandwidth
• CPC Class Codes: H04W 52/50 : at the moment of starting communication in a multiple access environment

Abstract

For transmit diversity in a multi-antenna OFDM system, a transmitter encodes, interleaves, and symbol maps traffic data to obtain data symbols. The transmitter processes each pair of data symbols to obtain two pairs of transmit symbols for transmission from a pair of antennas either (1) in two OFDM symbol periods for space-time transmit diversity or (2) on two subbands for space-frequency transmit diversity. N_T·(N_T−1)/2 different antenna pairs are used for data transmission, with different antenna pairs being used for adjacent subbands, where N_T is the number of antennas. The system may support multiple OFDM symbol sizes. The same coding, interleaving, and modulation schemes are used for different OFDM symbol sizes to simplify the transmitter and receiver processing. The transmitter performs OFDM modulation on the transmit symbol stream for each antenna in accordance with the selected OFDM symbol size. The receiver performs the complementary processing.

Claims

1. A method for processing data for transmission in a wireless multi-antenna orthogonal frequency division multiplexing (OFDM) communication system, comprising:

coding data bits of a data packet in accordance with a coding scheme to obtain coded data;

interleaving the coded data in accordance with an interleaving scheme to obtain interleaved data;

selecting at least one OFDM symbol size, from at least a first OFDM size associated with S subbands and a second OFDM symbol size associated with L subbands, wherein L is greater than S; and

processing the interleaved data, in accordance with the selected OFDM symbol size, to obtain a stream of OFDM symbols of the selected OFDM symbol size for transmission on one or more transmit antenna pairs using a transmit diversity scheme.

2. The method of claim 1, wherein L is an integer multiple of S.

3. The method of claim 2, wherein:

if the second OFDM symbol size is selected, processing the interleaved data comprises mapping subbands of the second OFDM symbol to subbands of the first OFDM symbol.

4. The method of claim 1, wherein:

selecting at least one OFDM symbol size comprises selecting the first and second OFDM symbol size; and

processing the interleaved data comprises obtaining a stream of OFDM symbols of the first and second OFDM symbol size for transmission using one or more transmit antenna pairs.

5. The method of claim 1, wherein:

the transmit diversity scheme comprises a space-time transmit diversity (STTD) scheme if the first OFDM size is selected; and

the transmit diversity scheme comprises a space-frequency transmit diversity (SFTD) scheme if the second OFDM size is selected.

6. The method of claim 5, wherein:

the STTD scheme is performed on a per-subband and per-OFDM-symbol-pair basis; and

the SFTD scheme is performed on a per-subband-pair and per-OFDM-symbol basis.

7. An apparatus for processing data for transmission in a wireless multi-antenna orthogonal frequency division multiplexing (OFDM) communication system, comprising:

logic for coding data bits of a data packet in accordance with a coding scheme to obtain coded data;

logic for interleaving the coded data in accordance with an interleaving scheme to obtain interleaved data;

logic for selecting at least one OFDM symbol size, from at least a first OFDM size associated with S subbands and a second OFDM symbol size associated with L subbands, wherein L is greater than S; and

logic for processing the interleaved data, in accordance with the selected OFDM symbol size, to obtain a stream of OFDM symbols of the selected OFDM symbol size for transmission on one or more transmit antenna pairs using a transmit diversity scheme.

8. The apparatus of claim 7, wherein L is an integer multiple of S.

9. The apparatus of claim 8, wherein:

the logic for processing the interleaved data is configured to map subbands of the second OFDM symbol to subbands of the first OFDM symbol if the second OFDM symbol size is selected.

10. The apparatus of claim 7, wherein:

the logic for selecting at least one OFDM symbol size comprises logic for selecting the first and second OFDM symbol size; and

the logic for processing the interleaved data comprises logic for obtaining a stream of OFDM symbols of the first and second OFDM symbol size for transmission using one or more transmit antenna pairs.

11. The apparatus of claim 7, wherein:

the transmit diversity scheme comprises a space-time transmit diversity (STTD) scheme if the first OFDM size is selected; and

the transmit diversity scheme comprises a space-frequency transmit diversity (SFTD) scheme if the second OFDM size is selected.

12. The apparatus of claim 11, wherein:

the STTD scheme is performed on a per-subband and per-OFDM-symbol-pair basis; and

the SFTD scheme is performed on a per-subband-pair and per-OFDM-symbol basis.

13. An apparatus for processing data for transmission in a wireless multi-antenna orthogonal frequency division multiplexing (OFDM) communication system, comprising:

means for coding data bits of a data packet in accordance with a coding scheme to obtain coded data;

means for interleaving the coded data in accordance with an interleaving scheme to obtain interleaved data;

means for selecting at least one OFDM symbol size, from at least a first OFDM size associated with S subbands and a second OFDM symbol size associated with L subbands, wherein L is greater than S; and

means for processing the interleaved data, in accordance with the selected OFDM symbol size, to obtain a stream of OFDM symbols of the selected OFDM symbol size for transmission on one or more transmit antenna pairs using a transmit diversity scheme.

14. The apparatus of claim 13, wherein L is an integer multiple of S.

15. The apparatus of claim 14, wherein:

the means for processing the interleaved data is configured to map subbands of the second OFDM symbol to subbands of the first OFDM symbol if the second OFDM symbol size is selected.

16. The apparatus of claim 13, wherein:

the means for selecting at least one OFDM symbol size comprises means for selecting the first and second OFDM symbol size; and

the means for processing the interleaved data comprises means for obtaining a stream of OFDM symbols of the first and second OFDM symbol size for transmission using one or more transmit antenna pairs.

17. The apparatus of claim 13, wherein:

the transmit diversity scheme comprises a space-time transmit diversity (STTD) scheme if the first OFDM size is selected; and

the transmit diversity scheme comprises a space-frequency transmit diversity (SFTD) scheme if the second OFDM size is selected.

18. The apparatus of claim 17, wherein:

the STTD scheme is performed on a per-subband and per-OFDM-symbol-pair basis; and

the SFTD scheme is performed on a per-subband-pair and per-OFDM-symbol basis.

19. A computer-program product for processing data for transmission in a wireless multi-antenna orthogonal frequency division multiplexing (OFDM) communication system, comprising a memory unit having software codes stored thereon, the software codes being executable by one or more processors for:

coding data bits of a data packet in accordance with a coding scheme to obtain coded data;

interleaving the coded data in accordance with an interleaving scheme to obtain interleaved data;

selecting at least one OFDM symbol size, from at least a first OFDM size associated with S subbands and a second OFDM symbol size associated with L subbands, wherein L is greater than S; and

processing the interleaved data, in accordance with the selected OFDM symbol size, to obtain a stream of OFDM symbols of the selected OFDM symbol size for transmission on one or more transmit antenna pairs using a transmit diversity scheme.

20. The computer-program product of claim 19, wherein L is an integer multiple of S.

21. The computer-program product of claim 20, wherein:

if the second OFDM symbol size is selected, processing the interleaved data comprises mapping subbands of the second OFDM symbol to subbands of the first OFDM symbol.

22. The computer-program product of claim 19, wherein:

selecting at least one OFDM symbol size comprises selecting the first and second OFDM symbol size; and

processing the interleaved data comprises obtaining a stream of OFDM symbols of the first and second OFDM symbol size for transmission using one or more transmit antenna pairs.

23. The computer-program product of claim 19, wherein:

the transmit diversity scheme comprises a space-time transmit diversity (STTD) scheme if the first OFDM size is selected; and

the transmit diversity scheme comprises a space-frequency transmit diversity (SFTD) scheme if the second OFDM size is selected.

24. The computer-program product of claim 23, wherein:

the STTD scheme is performed on a per-subband and per-OFDM-symbol-pair basis; and

the SFTD scheme is performed on a per-subband-pair and per-OFDM-symbol basis.