Precoding for segment sensitive scheduling in wireless communication systems

• US 8,639,190 B2
• Filed: 10/27/2006
• Issued: 01/28/2014
• Est. Priority Date: 10/27/2005
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Gore, Dhananjay Ashok, Sampath, Hemanth, Wang, Jibing, Kadous, Tamer, Barriac, Gwendolyn D.
• Primary Examiner(s): Pham, Tuan
• Application Number:
  US11/553,870
• Publication Number:
  US 20070098099A1
• Time in Patent Office: 2,650 Days
• Field of Search: 455/550.1, 455/424, 455/425, 455/456.5, 455/456.6, 455/561, 455/42, 455/17, 455/23, 455/69, 455/70, 455/78, 455/126, 455/103, 455/110, 455/115.1, 455/108, 455/39, 455/67.11, 455/73, 455/91, 455/101, 455/130, 375/146, 375/221, 375/239, 375/300, 375/302, 375/260, 375/267, 332/103, 332/118, 332/144, 332/162, 332/117
• US Class Current: 455/69
• CPC Class Codes: H04B 7/0456 Selection of precoding matrices or codebooks, e.g. using matrices antenna weighting
• CPC Class Codes: H04L 1/0016 involving special memory structures, e.g. look-up tables
• CPC Class Codes: H04L 1/0026 Transmission of channel quality indication
• CPC Class Codes: H04L 1/0675 characterised by the signaling
• CPC Class Codes: H04L 25/0204 of multiple channels
• CPC Class Codes: H04L 27/2602 Signal structure
• CPC Class Codes: H04L 5/0044 allocation of payload
• CPC Class Codes: H04L 5/023 Multiplexing of multicarrier modulation signals multicarrier modulation H04L27/2601
• CPC Class Codes: Y02D 30/70 in wireless communication networks

Abstract

Techniques to enhance the performance in a wireless communication system using segments called subbands and using precoding are shown. According to one aspect, the bandwidth for transmission to an access terminal is constrained to a preferred bandwidth which is less than the bandwidth available for transmission to an access terminal and precoding information related to the subcarriers within the constrained bandwidth is provided to a transmitter. The precoding information related to the subcarriers within a constrained bandwidth provides feedback about the forward link channel properties relative to different subbands and may be fed back on a channel associated with the bandwidth.

Claims

1. A wireless communication apparatus comprising:

a processor configured to decode signals that are received over two or more subcarriers of a segment of subcarriers, which is one of a plurality of segments of subcarriers available for communication, and to provide precoding weights for at least one segment of the plurality of segments based on the received signal, wherein the precoding weights are applied to at least one symbol of at least one data stream based upon at least one channel response information of a user and wherein the at least one segment is a subband which comprises a predetermined bandwidth; and

a transmitter configured to transmit the precoding weights, wherein each segment of subcarriers of the plurality of segments of subcarriers has its own feedback channel, and wherein the transmitter is configured to feedback to a receiver the precoding weights for each of the at least one segment on the segment'"'"'s own feedback channel.

2. The wireless communication apparatus of claim 1, wherein the processor is configured to provide the precoding weights as a precoding index.

3. The wireless communication apparatus of claim 2, wherein the processor is configured to determine a signal to noise ratio and select, to provide, a precoding index as a function of the signal to noise ratio.

4. The wireless communication apparatus of claim 1, wherein the processor is configured to provide precoding weights for at least one other segment of subcarriers in addition to the segment including the one or more subcarriers.

5. The wireless communication apparatus of claim 1, wherein the segment comprises a subband.

6. A wireless communication method comprising:

receiving signals over two or more subcarriers of a segment of subcarriers, which is one of one or more segments of subcarriers;

generating precoding weights for at least one segment of the one or more segments, based upon the received signal, wherein the precoding weights are applied to at least one symbol of at least one data stream based upon at least one channel response information of a user and wherein the at least one segment is a subband which comprises a predetermined bandwidth; and

transmitting the precoding weights, wherein each segment of subcarriers of the one or more segments of subcarriers has its own feedback channel, and wherein the transmitter is configured to feedback to a receiver the precoding weights for each of the at least one segment on the segment'"'"'s own feedback channel.

7. The method of claim 6 wherein generating comprises generating the precoding weights as a precoding index.

8. The method of claim 7, wherein generating comprises determining a signal to noise ratio and selecting a precoding index as a function of the signal to noise ratio.

9. The method of claim 6, wherein generating comprises generating precoding weights for at least one other segment of subcarriers in addition to the segment including the one or more subcarriers.

10. The method of claim 6, wherein the segment comprises a subband.

11. A wireless communication device comprising:

means for receiving signals over two or more subcarriers of a segment of subcarriers, which is one of one or more segments of subcarriers;

means for generating precoding weights for at least one segment of the one or more segments, based upon the received signal, wherein the precoding weights are applied to at least one symbol of at least one data stream based upon at least one channel response information of a user and wherein the at least one segment is a subband which comprises a predetermined bandwidth; and

means for transmitting the precoding weights, wherein each segment of subcarriers of the one or more segments of subcarriers has its own feedback channel, and wherein the transmitter is configured to feedback to a receiver the precoding weights for each of the at least one segment on the segment'"'"'s own feedback channel.

12. The wireless communication apparatus of claim 11, wherein generating comprises generating the precoding weights as a precoding index.

13. The wireless communication apparatus of claim 12, wherein generating comprises determining a signal to noise ratio and selecting a precoding index as a function of the signal to noise ratio.

14. The wireless communication apparatus of claim 11, wherein generating comprises generating precoding weights for at least one other segment of subcarriers in addition to the segment including the one or more subcarriers.

15. A non-transitory computer-readable medium storing a computer program, wherein execution of the computer program is for:

receiving signals over two or more subcarriers of a segment of subcarriers, which is one of one or more segments of subcarriers;

generating precoding weights for at least one segment of the one or more segments, based upon the received signal, wherein the precoding weights are applied to at least one symbol of at least one data stream based upon at least one channel response information of a user and wherein the at least one segment is a subband which comprises a predetermined bandwidth; and

transmitting the precoding weights, wherein each segment of subcarriers of the one or more segments of subcarriers has its own feedback channel, and wherein the transmitter is configured to feedback to a receiver the precoding weights for each of the at least one segment on the segment'"'"'s own feedback channel.