Diversity transmission modes for MIMO OFDM communication systems

• US 20030235147A1
• Filed: 06/24/2002
• Published: 12/25/2003
• Est. Priority Date: 06/24/2002
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Ketchum, John W., Walton, Jay R.
• Granted Patent: US 7,095,709 B2
• Time in Patent Office: Days
• US Class Current: 370/204
• CPC Class Codes: H04B 7/04 using two or more spaced independent antennas
• CPC Class Codes: H04B 7/0669 using different channel coding between antennas 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 7/0697 using spatial multiplexing
• CPC Class Codes: H04L 1/0001 Systems modifying transmission characteristics according to link quality, e.g. power backoff adaptive data allocation for multicarrier modulation H04L5/0044; controlling transmission power for radio systems H04W52/04
• CPC Class Codes: H04L 1/0618 Space-time coding
• CPC Class Codes: H04L 5/0007 the frequencies being orthogonal, e.g. OFDM(A), DMT
• CPC Class Codes: H04L 5/0016 Time-frequency-code
• CPC Class Codes: H04L 5/0023 Time-frequency-space
• CPC Class Codes: H04L 5/0028 Variable division signaling therefor H04L5/0092

Abstract

Techniques for transmitting data using a number of diversity transmission modes to improve reliability. At a transmitter, for each of one or more data streams, a particular diversity transmission mode is selected for use from among a number of possible transmission modes. These transmission modes may include a frequency diversity transmission mode, a Walsh diversity transmission mode, a space time transmit diversity (STTD) transmission mode, and a Walsh-STTD transmission mode. Each diversity transmission mode redundantly transmits data over time, frequency, space, or a combination thereof. Each data stream is coded and modulated to provide modulation symbols, which are further processed based on the selected diversity transmission mode to provide transmit symbols. For OFDM, the transmit symbols for all data streams are further OFDM modulated to provide a stream of transmission symbols for each transmit antenna used for data transmission.

Claims

1. A method for processing data for transmission in a wireless communication system, comprising:

selecting a particular diversity transmission mode from among a plurality of possible transmission modes to use for each of one or more data streams, wherein each selected diversity transmission mode redundantly transmits data over time, frequency, space, or a combination thereof;

coding and modulating each data stream based on coding and modulation schemes selected for the data stream to provide modulation symbols; and

processing the modulation symbols for each data stream based on the selected diversity transmission mode to provide transmit symbols for transmission over one or more transmit antennas.

2. The method of claim 1, wherein the plurality of possible transmission modes includes a frequency diversity transmission mode.

3. The method of claim 1, wherein the plurality of possible transmission modes includes a Walsh diversity transmission mode.

4. The method of claim 3, wherein the Walsh diversity transmission mode transmits each modulation symbol over N_T symbol periods, where N_T is the number of transmit antennas used for data transmission.

5. The method of claim 4, wherein the Walsh diversity transmission mode transmits each modulation symbol over all N_T transmit antennas.

6. The method of claim 1, wherein the plurality of possible transmission modes includes a space time transmit diversity (STTD) transmission mode.

7. The method of claim 1, wherein the plurality of possible transmission modes includes a Walsh-STTD transmission mode.

8. The method of claim 1, wherein the plurality of possible transmission modes includes a frequency-STTD transmission mode.

9. The method of claim 7, wherein the Walsh-STTD transmission mode redundantly transmits modulation symbols over a plurality of pairs of transmit antennas.

10. The method of claim 7, wherein the Walsh-STTD transmission mode transmits different modulation symbols over different pairs of transmit antennas.

11. The method of claim 1, wherein the wireless communication system is a multiple-input multiple-output (MIMO) communication system, and wherein the transmit symbols for the one or more data streams are transmitted over a plurality of transmit antennas.

12. The method of claim 11, wherein the MIMO communication system utilizes orthogonal frequency division multiplexing (OFDM).

13. The method of claim 12, further comprising:

OFDM modulating the transmit symbols for the one or more data streams to provide a stream of transmission symbols for each transmit antenna used for data transmission.

14. The method of claim 12, wherein the transmit symbols for each data stream are transmitted on a respective group of one or more subbands.

15. The method of claim 1, wherein at least one data stream is transmitted for an overhead channel.

16. The method of claim 14, wherein the data stream for a broadcast channel is transmitted based on a fixed diversity transmission mode.

17. The method of claim 1, wherein at least one data stream is user-specific and transmitted for a specific receiver device.

18. The method of claim 17, wherein data rate for each of the at least one user-specific data stream is adjusted based on transmission capability of the specific receiver device.

19. The method of claim 1, further comprising:

multiplexing pilot symbols with the modulation symbols for the one or more data streams.

20. The method of claim 1, wherein the pilot symbols are multiplexed with the modulation symbols using frequency division multiplexing (FDM).

21. A method for processing data for transmission in a multiple-input multiple-output (MIMO) communication system that utilizes orthogonal frequency division multiplexing (OFDM), comprising:

selecting a particular diversity transmission mode from among a plurality of possible transmission modes to use for each of one or more data streams, wherein each selected diversity transmission mode redundantly transmits data over time, frequency, space, or a combination thereof by using frequency diversity, Walsh transmit diversity, space time transmit diversity (STTD), or any combination thereof;

coding and modulating each data stream based on coding and modulation schemes selected for the data stream to provide modulation symbols; and

processing the modulation symbols for each data stream based on the selected diversity transmission mode to provide transmit symbols for transmission over a plurality of transmit antennas.

22. The method of claim 21, wherein the plurality of possible transmission modes includes a frequency diversity transmission mode, a Walsh diversity transmission mode, and a STTD transmission mode.

23. The method of claim 22, wherein the plurality of possible transmission modes further includes a Walsh-STTD transmission mode.

24. A method for processing data for transmission in a multiple-input multiple-output (MIMO) communication system that utilizes orthogonal frequency division multiplexing (OFDM), comprising:

coding and modulating data to provide one or more substreams of modulation symbols for each of a plurality of OFDM subbands; and

for each of the plurality of OFDM subbands, processing the modulation symbols in the one or more substreams for the OFDM subband to provide transmit symbols,

wherein the modulation symbols are processed in accordance with a particular diversity processing scheme selected for the OFDM subband to provide diversity in time, frequency, space, or a combination thereof.

25. The method of claim 24, wherein the selected diversity processing scheme for at least one OFDM subband is a space time transmit diversity (STTD) scheme.

26. The method of claim 24, wherein the selected diversity processing scheme for at least one OFDM subband is a Walsh transmit diversity scheme.

27. The method of claim 24, wherein the selected diversity processing scheme for at least one OFDM subband is a Walsh-space time transmit diversity (Walsh-STTD) scheme.

28. A method for processing a data transmission at a receiver of a wireless communication system, comprising:

determining a particular diversity transmission mode used for each of one or more data streams to be recovered from a received data transmission, wherein the diversity transmission mode used for each data stream is selected from among a plurality of possible transmission modes, and wherein each diversity transmission mode redundantly transmits data over time, frequency, space, or a combination thereof; and

processing received symbols for each data stream based on the diversity transmission mode used for the data stream to provide recovered symbols that are estimates of modulation symbols transmitted from a transmitter for the data stream.

29. The method of claim 28, wherein the plurality of possible transmission modes includes a frequency diversity transmission mode, a Walsh diversity transmission mode, and a space time transmit diversity (STTD) transmission mode.

30. The method of claim 29, wherein the plurality of possible transmission modes further includes a Walsh-STTD transmission mode.

31. The method of claim 29, wherein the plurality of possible transmission modes further includes a frequency-STTD transmission mode.

32. The method of claim 28, further comprising:

demodulating and decoding the recovered symbols for each data stream to provide decoded data.

33. A memory communicatively coupled to a digital signal processing device (DSPD) capable of interpreting digital information to:

select a particular diversity transmission mode from among a plurality of possible transmission modes to use for each of one or more data streams, wherein each selected diversity transmission mode redundantly transmits data over time, frequency, space, or a combination thereof;

code and modulate each data stream based on coding and modulation schemes selected for the data stream to provide modulation symbols; and

process the modulation symbols for each data stream based on the selected diversity transmission mode to provide transmit symbols for transmission over one or more transmit antennas.

34. A transmitter unit in a wireless communication system, comprising:

a controller operative to select a particular diversity transmission mode from among a plurality of possible transmission modes to use for each of one or more data streams, wherein each selected diversity transmission mode redundantly transmits data over time, frequency, space, or a combination thereof;

a TX data processor operative to code and modulate each data stream based on coding and modulation schemes selected for the data stream to provide modulation symbols; and

a transmit processor operative to process the modulation symbols for each data stream based on the selected diversity transmission mode to provide transmit symbols for transmission over one or more transmit antennas.

35. The transmitter unit of claim 34, wherein the plurality of possible transmission modes includes a frequency diversity transmission mode, a Walsh diversity transmission mode, and a space time transmit diversity (STTD) transmission mode.

36. The transmitter unit of claim 35, wherein the plurality of possible transmission modes further includes a Walsh-STTD transmission mode.

37. The transmitter unit of claim 35, wherein the plurality of possible transmission modes further includes a frequency-STTD transmission mode.

38. The transmitter unit of claim 34, wherein the wireless communication system is a multiple-input multiple-output (MIMO) communication system that utilizes orthogonal frequency division multiplexing (OFDM).

39. The transmitter unit of claim 38, wherein the transmit processor is further operative to OFDM modulate the transmit symbols for the one or more data streams to provide a stream of transmission symbols for each transmit antenna used for data transmission.

40. An access point comprising the transmitter unit of claim 34.

41. A terminal comprising the transmitter unit of claim 34.

42. An apparatus in a multiple-input multiple-output (MIMO) communication system, comprising:

means for selecting a particular diversity transmission mode from among a plurality of possible transmission modes to use for each of one or more data streams,

wherein each selected diversity transmission mode redundantly transmits data over time, frequency, space, or a combination thereof;

means for coding and modulating each data stream based on coding and modulation schemes selected for the data stream to provide modulation symbols; and

means for processing the modulation symbols for each data stream based on the selected diversity transmission mode to provide transmit symbols for transmission over one or more transmit antennas.

43. The apparatus of claim 42, wherein the plurality of possible transmission modes includes a frequency diversity transmission mode, a Walsh diversity transmission mode, and a space time transmit diversity (STTD) transmission mode.

44. A receiver unit in a wireless communication system, comprising:

a controller operative to determine a particular diversity transmission mode used for each of one or more data streams to be recovered from a received data transmission,

wherein the diversity transmission mode used for each data stream is selected from among a plurality of possible transmission modes, and wherein each diversity transmission mode redundantly transmits data over time, frequency, space, or a combination thereof; and

a receive processor operative to process received symbols for each data stream based on the diversity transmission mode used for the data stream to provide recovered symbols that are estimates of modulation symbols transmitted from a transmitter for the data stream.

45. The receiver unit of claim 44, further comprising:

a receive data processor operative to demodulate and decode the recovered symbols for each data stream to provide decoded data.

46. The receiver unit of claim 44, wherein the plurality of possible transmission modes includes a frequency diversity transmission mode, a Walsh diversity transmission mode, and a space time transmit diversity (STTD) transmission mode.

47. An access point comprising the receiver unit of claim 44.

48. A terminal comprising the receiver unit of claim 44.

49. A receiver apparatus in a wireless communication system, comprising:

means for determining a particular diversity transmission mode used for each of one or more data streams to be recovered from a received data transmission, wherein the diversity transmission mode used for each data stream is selected from among a plurality of possible transmission modes, and wherein each diversity transmission mode redundantly transmits data over time, frequency, space, or a combination thereof; and

means for processing received symbols for each data stream based on the diversity transmission mode used for the data stream to provide recovered symbols that are estimates of modulation symbols transmitted from a transmitter for the data stream.