Transmission schemes for multi-antenna communication systems utilizing multi-carrier modulation

• US 7,095,790 B2
• Filed: 02/25/2003
• Issued: 08/22/2006
• Est. Priority Date: 02/25/2003
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Krishnan, Ranganathan, Kadous, Tamer, Subramaniam, Anand D.
• Primary Examiner(s): TSE, YOUNG TOI
• Application Number:
  US10/375,191
• Publication Number:
  US 20040165676A1
• Time in Patent Office: 1,274 Days
• Field of Search: 375/135, 375/146, 375/267, 375/299, 370/208, 370/209, 370/210, 370/320, 370/335, 370/342, 455/101, 455/500
• US Class Current: 375/260
• CPC Class Codes: H04B 7/0667 of delayed versions of same signal using space-time coding H04L1/0618
• CPC Class Codes: H04L 5/0023 Time-frequency-space
• CPC Class Codes: H04L 5/0048 Allocation of pilot signals, i.e. of signals known to the receiver
• CPC Class Codes: H04W 52/42 in systems with time, space, frequency or polarisation diversity

Abstract

Pilot and data transmission schemes for multi-antenna communication systems utilizing multi-carrier modulation are provided. Subband multiplexing is used to avoid interference resulting from transmitting multiple signals simultaneously from multiple antennas. M usable subbands are initially arranged to form multiple groups of subbands, with each group including a different subset of the usable subbands. Each of T transmit antennas is then assigned one or possibly more subband groups for pilot transmission and typically one subband group for data transmission. Pilot and data may then be transmitted from each antenna on the subbands assigned to that antenna for pilot and data transmission. For each transmit antenna, the transmit power for each assigned subband may be scaled higher such that all of the total transmit power available for the antenna is used for transmission. Pilot and/or data may be transmitted simultaneously from all T antennas on all usable subbands without causing mutual interference.

Claims

1. A method of transmitting from a multi-antenna communication device, comprising:

forming a plurality of groups of subbands with a plurality of subbands, wherein each of the plurality of groups includes a different subset of the plurality of subbands;

assigning each of a plurality of antennas with a different one of the plurality of groups; and

transmitting from the plurality of antennas simultaneously using the plurality of groups of subbands, wherein the transmitting from each antenna occurs on the group of subbands assigned to the antenna,

wherein for each antenna, a transmit power used for each of the subbands in the group assigned to the antenna is scaled higher than an average power obtained by distributing total transmit power across the plurality of subbands.

2. The method of claim 1, wherein pilot is transmitted from each antenna on the group of subbands assigned to the antenna.

3. The method of claim 1, wherein each of the plurality of groups includes the same number of subbands.

4. The method of claim 1, wherein the subbands in each of the plurality of groups are uniformly distributed across the plurality of subbands.

5. The method of claim 1, wherein the multi-antenna communication device utilizes orthogonal frequency division multiplexing (OFDM).

6. The method of claim 1, wherein each of the plurality of groups includes at least two disjoint subbands.

7. A method of transmitting data from a multi-antenna communication apparatus comprising:

forming a plurality of groups of subbands with a plurality of subbands, wherein each of the plurality of groups includes a different subset of the plurality of subbands;

assigning each of a plurality of antennas with one of the plurality of groups; and

transmitting data from the plurality of antennas simultaneously using the plurality of groups of subbands, wherein data is transmitted from each antenna on the group of subbands assigned to the antenna, and wherein data is transmitted on each of the plurality of subbands by a particular group of at least two antennas,

wherein for each antenna, a transmit power used for each of the subbands in the group assigned to the antenna is scaled higher than an average power obtained by distributing total transmit power across the plurality of subbands.

8. The method of claim 7, wherein each of the plurality of groups includes the same number of subbands.

9. The method of claim 7, wherein the subbands in each of the plurality of groups are uniformly distributed across the plurally of subbands.

10. The method of claim 7, wherein each of the plurality of antennas is assigned a different one of the plurality of groups.

11. The method of claim 7, wherein each pair of antennas in the plurality of antennas is assigned a different one of the plurality of groups.

12. The method of claim 7, wherein data is transmitted on each of the plurality of subbands by a particular group of two antennas.

13. The method of claim 7, further comprising:

processing data using space-time transmit diversity (STTD) encoding to provide two streams of symbols; and

demultiplexing the two streams of symbols to provide a plurality of substreams of symbols, one substream for each of the plurality of antennas, wherein the demultiplexing is performed based on the group of subbands assigned to each antenna, and wherein each substream of symbols is transmitted from an associated antenna.

14. The method of claim 7, further comprising:

processing data using Walsh space-time transmit diversity (STTD)) encoding to provide W streams of symbols, where W is greater than two; and

demultiplexing the W streams of symbols to provide a plurality of substreams of symbols, one substream for each of the plurality of antennas, wherein the demultiplexing is performed based on the group of subbands assigned to each antenna, and wherein each substream of symbols is transmitted from an associated antenna.

15. The method of claim 7, wherein the multi-antenna communication apparatus utilizes orthogonal frequency division multiplexing (OFDM).

16. The method of claim 7, wherein each of the plurality of groups includes at least two disjoint subbands.

17. An apparatus used in a multi-antenna communication system, comprising

means for assigning each of a plurality of antennas with at least one of a plurality of groups of subbands, wherein the plurality of groups of subbands are formed from a plurality of subbands, and wherein each of the plurality of groups includes a different subset of the plurality of subbands;

and

means for transmitting from the plurality of antennas simultaneously using the plurality of groups of subbands, wherein transmission from each antenna occurs on the at least one group of subbands assigned to the antenna and in a manner to avoid interference among the plurality of antennas,

wherein for each antenna, a transmit power used for each of the subbands in the group assigned to the antenna is scaled higher than an average power obtained by distributing total transmit power across the plurality of subbands.

18. The apparatus of claim 17, wherein each of the plurality of antennas is assigned a different one of the plurality of groups.

19. The apparatus of claim 17, wherein each of the plurality of antennas is assigned at least two groups of the plurality of groups, and wherein each of the at least two groups is used for a different symbol period.

20. The apparatus of claim 17, wherein for each symbol period the transmission for each of the plurality of subbands occurs from one of the plurality of antennas.

21. The apparatus of claim 17, wherein each of the plurality of groups includes at least two disjoint subbands.

22. A method of transmitting from a multi-antenna device, comprising:

assigning a different group of a plurality of groups of subbands to each of a plurality of antennas, wherein each group of the plurality of groups is formed by a different subset of a plurality of subbands; and

transmitting from the plurality of antennas using the different group of subbands, wherein a transmit power used for at least one subband in the group assigned to each antenna is scaled higher than an average power obtained by distributing total transmit power across the plurality of subbands.

23. The method of claim 22, wherein pilot is transmitted from each antenna on at least one subband of the group of subbands assigned to the antenna.

24. The method of claim 22, wherein each of the plurality of groups includes a same number of subbands.

25. The method of claim 22, wherein the subbands in each of the plurality of groups are uniformly distributed across the plurality of subbands.

26. The method of claim 22 wherein the multi-antenna device utilizes orthogonal frequency division multiplexing (OFDM).

27. The method of claim 22 wherein each of the plurality of groups includes at least two disjoint subbands.

28. A device, comprising:

a memory; and

a processor coupled with the memory, the processor capable of assigning a different group of a plurality of groups of subbands to each of a plurality of antennas, wherein each group of the plurality of groups is formed by a different subset of a plurality of subbands, and the processor further capable of setting a transmit power for at least one subband in each group assigned to each antenna to be scaled higher than an average power obtained by distributing total transmit power across the plurality of subbands.

29. The device of claim 28, wherein the processor assigns pilot to be transmitted from each antenna on a least one subband of the group of subbands assigned to the antenna.

30. The device of claim 28, wherein each of the plurality of groups includes a same number of subbands.

31. The device of claim 28, wherein the subbands in each of the plurality of groups are uniformly distributed across the plurality of subbands.

32. The device of claim 28, wherein each of the plurality of groups includes at least two disjoint subbands.