Diversity transmission modes for MIMO OFDM communication systems

• US 20060193268A1
• Filed: 04/10/2006
• Published: 08/31/2006
• 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 7,990,841 B2
• Time in Patent Office: Days
• US Class Current: 370/264
• 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 from a wireless communication apparatus, comprising:

selecting a diversity transmission mode from among a plurality of diversity transmission modes, wherein the plurality of diversity of transmission modes include a space-time transmit diversity mode where space time transmit diversity is used to transit a first pair of transmission symbols using a first pair of antennas and a second pair of transmission symbols using a second pair of antennas, wherein the first pair of antennas are different from the second pair of antennas;

coding and modulating at least one data stream to provide first and second pairs of modulation symbols; and

processing the first pair of modulation symbols based on the space-time diversity transmission mode to provide the first pair of transmission symbols for transmission over the first pair of antennas and the second pair of modulation symbols based on the space-time diversity mode to provide the second pair of transmission symbols for transmission over the second pair of antennas.

2. The method of claim 1, wherein the first pair of modulation symbols and the second pair of modulation symbols are transmitted over different subbands.

3. The method of claim 1, wherein at least one symbol of the first pair of modulation symbols and the second pair of modulation symbols is a same modulation symbol.

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

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

6. The method of claim 1, wherein the at least one data stream corresponds an overhead channel.

7. The method of claim 1, wherein selecting comprises selecting based upon a type of the at least one data stream.

8. The method of claim 1, wherein selecting comprises selecting based upon a type of terminal received one of the first pair and second pair of modulation symbols.

9. The method of claim 1, wherein selecting comprises selecting based upon a mix of terminal types in communication with an access point.

10. The method of claim 1, wherein selecting comprises selecting either one of the plurality of diversity transmission modes or a spatial multiplexing mode.

11. The method of claim 1, wherein selecting comprises selecting based upon channel information.

12. The method of claim 1, further comprising multiplexing pilot symbols with the modulation symbols.

13. The method of claim 1, wherein coding comprises utilizing a turbo code.

14. The method of claim 1, wherein coding comprises utilizing a convolutional code.

15. A transmitter unit An apparatus in a wireless communication system, comprising:

a controller configured to select a diversity transmission mode from among a plurality of diversity transmission modes, wherein the plurality of diversity of transmission modes include a space-time transmit diversity mode where space time transmit diversity is used to transmit a first pair of transmission symbols using a first pair of antennas and a second pair of transmission symbols using a second pair of antennas, wherein the first pair of antennas are different from the second pair of antennas;

a processor configured to code and modulate at least one data stream to provide first and second pairs of modulation symbols; and

another processor configured to process the first pair of modulation symbols based on the space-time diversity transmission mode to provide the first pair of transmission symbols for transmission over the first pair of antennas and the second pair of modulation symbols based on the space-time diversity mode to provide the second pair of transmission symbols for transmission over the second pair of antennas.

16. The apparatus of claim 15, wherein the first pair of modulation symbols and the second pair of modulation symbols are transmitted over different subbands.

17. The apparatus of claim 15, wherein at least one symbol of the first pair of modulation symbols and the second pair of modulation symbols is a same modulation symbol.

18. The apparatus of claim 15, wherein the plurality of diversity transmission modes further includes a frequency diversity transmission mode.

19. The apparatus of claim 15, wherein the plurality of diversity transmission modes further includes a Walsh diversity transmission mode.

20. The apparatus of claim 15, wherein the at least one data stream corresponds an overhead channel.

21. The apparatus of claim 15, wherein the controller is configured to select based upon a type of the at least one data stream.

22. The apparatus of claim 15, wherein the controller is configured to select based upon a type of terminal received one of the first pair and second pair of modulation symbols.

23. The apparatus of claim 15, wherein the controller is configured to select based upon a mix of terminal types in communication with an access point.

24. The apparatus of claim 15, wherein the controller is configured to select either one of the plurality of diversity transmission modes or a spatial multiplexing mode.

25. The apparatus of claim 24, wherein the controller is configured to select based upon channel information.

26. An apparatus comprising:

means for selecting a diversity transmission mode from among a plurality of diversity transmission modes, wherein the plurality of diversity of transmission modes include a space-time transmit diversity mode where space time transmit diversity is used to transit a first pair of transmission symbols using a first pair of antennas and a second pair of transmission symbols using a second pair of antennas, wherein the first pair of antennas are different from the second pair of antennas;

a processor configured to code and modulate at least one data stream to provide first and second pairs of modulation symbols; and

means for processing the first pair of modulation symbols based on the space-time diversity transmission mode to provide the first pair of transmission symbols for transmission over the first pair of antennas and the second pair of modulation symbols based on the space-time diversity mode to provide the second pair of transmission symbols for transmission over the second pair of antennas.

27. The apparatus of claim 26, wherein the first pair of modulation symbols and the second pair of modulation symbols are transmitted over different subbands.

28. The apparatus of claim 26, wherein at least one symbol of the first pair of modulation symbols and the second pair of modulation symbols is a same modulation symbol.

29. The apparatus of claim 26, wherein the plurality of diversity transmission modes further includes a frequency diversity transmission mode.

30. The apparatus of claim 26, wherein the at least one data stream corresponds an overhead channel.

31. The apparatus of claim 26, wherein the means for selecting comprises means for selecting based upon a type of the at least one data stream.

32. The apparatus of claim 26, wherein the means for selecting comprises means for selecting based upon a type of terminal received one of the first pair and second pair of modulation symbols.

33. The apparatus of claim 26, wherein the means for selecting comprises means for selecting based upon a mix of terminal types in communication with an access point.

34. The apparatus of claim 26, wherein the means for selecting comprises means for selecting either one of the plurality of diversity transmission modes or a spatial multiplexing mode.

35. The apparatus of claim 34, wherein the means for selecting comprises means for selecting based upon channel information.

36. A method for processing data for transmission from a wireless communication apparatus, comprising:

providing two pairs of modulation symbols;

processing each pair of modulation symbols according to a space-time diversity transmission mode to provide a first pair of transmission symbols from the two pairs of modulation symbols and a second pair of transmission symbols from the two pairs of modulation symbols; and

providing the first pair of transmission symbols for transmission using a first pair of antennas and the second pair of transmission symbols for transmission using a second pair of antennas, wherein the first pair of antennas is different from the second pair of antennas.

37. The method of claim 36, wherein the first pair of transmission symbols and the second pair of transmission symbols are transmitted over different subbands.

38. The method of claim 36, wherein the two pairs of modulation symbols correspond to an overhead channel.

39. The method of claim 36, wherein providing two pairs of modulation symbols comprises coding comprises utilizing a turbo code.

40. The method of claim 36, wherein providing two pairs of modulation symbols comprises utilizing a convolutional code.

41. The method of claim 36, wherein processing comprises processing a first pair of the two pairs of modulation symbols to form the first pair of transmission symbols and a second pair of the two pairs of modulation symbols to form the second pair of transmission symbols.

42. The method of claim 41, wherein at least one symbol of the first pair of modulation symbols and the second pair of modulation symbols is a same modulation symbol.

43. A wireless communication apparatus, comprising:

a first processor configured to provide two pairs of modulation symbols; and

a second processor configured to process each pair of modulation symbols according to a space-time diversity transmission mode to provide a first pair of transmission symbols from the two pairs of modulation symbols and a second pair of transmission symbols from the two pairs of modulation symbols and to provide the first pair of transmission symbols for transmission using a first pair of antennas and the second pair of transmission symbols for transmission using a second pair of antennas, wherein the first pair of antennas are different from the second pair of antennas.

44. The apparatus of claim 43, further comprising a controller configured to transmit the first pair of transmission symbols and the second pair of transmission symbols over different subbands.

45. The apparatus of claim 43, wherein the two pairs of modulation symbols correspond to an overhead channel.

46. The apparatus of claim 43, wherein the first processor is configure to utilize a turbo code to provide the two pairs of modulation symbols.

47. The apparatus of claim 43, wherein the first processor is configure to utilize a convolutional code to provide the two pairs of modulation symbols.

48. The apparatus of claim 43, wherein the second processor is configure to process a first pair of the two pairs of modulation symbols to form the first pair of transmission symbols and a second pair of the two pairs of modulation symbols to form the second pair of transmission symbols.

49. The apparatus of claim 48, wherein at least one symbol of the first pair of modulation symbols and the second pair of modulation symbols is a same modulation symbol.

50. An apparatus for processing data for transmission from a wireless communication apparatus, comprising:

means for providing two pairs of nodulation symbols;

means for utilizing a space-time diversity transmission mode to provide a first pair of transmission symbols from the two pairs of modulation symbols and a second pair of transmission symbols from the two pairs of modulation symbols; and

means for providing the first pair of transmission symbols for transmission using a first pair of antennas and the second pair of transmission symbols for transmission using a second pair of antennas, wherein the first pair of antennas is different from the second pair of antennas.

51. The apparatus of claim 50, wherein the first pair of transmission symbols and the second pair of transmission symbols are transmitted over different subbands.

52. The apparatus of claim 50, wherein the two pairs of modulation symbols correspond to an overhead channel.

53. The apparatus of claim 50, wherein the means for utilizing comprises processing a first pair of the two pairs of modulation symbols to form the first pair of transmission symbols and a second pair of the two pairs of modulation symbols to form the second pair of transmission symbols.

54. The apparatus of claim 53, wherein at least one symbol of the first pair of modulation symbols and the second pair of modulation symbols is a same modulation symbol.