Channel quality feedback mechanism and method

• US 7,551,898 B2
• Filed: 05/19/2006
• Issued: 06/23/2009
• Est. Priority Date: 02/19/2002
• Status: Expired due to Term

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Lundby, Stein A., Puig-Oses, David, Odenwalder, Joseph P., Gaal, Peter
• Primary Examiner(s): Phu; Sanh D
• Application Number:
  US11/438,241
• Publication Number:
  US 20060211378A1
• Time in Patent Office: 1,131 Days
• Field of Search: 455/67.11, 455/67.13, 455/69, 455/63.1, 455/450, 455/452.2, 375/140, 375/141, 375/142, 375/143, 375/145, 375/146, 370/311, 370/328
• US Class Current: 455/67.13
• CPC Class Codes: H04B 17/24 with feedback of measurements to the transmitter
• CPC Class Codes: H04B 17/309 Measuring or estimating channel quality parameters
• CPC Class Codes: H04W 52/146 Uplink power control
• CPC Class Codes: H04W 72/54 based on quality criteria

Abstract

Methods and apparatus are presented for improving the feedback of channel information to a serving base station, which allows a reduction in the reverse link load while allowing the base station to improve the forward link data throughput. Over a channel quality indicator channel, three subchannels are generated; the re-synch subchannel, the differential feedback subchannel, and the transition indicator subchannel. The information carried on each subchannel can be used separately or together by a base station to selectively update internal registers storing channel conditions. The channel conditions are used to determine transmission formats, power levels, and data rates of forward link transmissions.

Claims

1. In a wireless communication system, an apparatus for scheduling forward link transmissions, comprising:

a memory element; and

a processing element configured to execute a set of instructions stored on the memory element, the set of instructions for;

receiving a full channel quality value and a plurality of incremental channel quality values from a remote station on a channel quality indicator channel (CQICH), wherein the full channel value is received concurrently with more than one incremental channel quality value and wherein the plurality of incremental channel quality values are received sequentially;

selectively updating a register with a channel quality estimate, wherein the channel quality estimate is based upon the full channel quality value and the plurality of incremental channel quality values;

determining power levels and data transmission rates for forward link transmissions in accordance with the updated register; and

scheduling forward link transmissions in accordance with the updated register.

2. The apparatus of claim 1, wherein selectively updating the register with the channel quality estimate comprises:

sequentially adding the plurality of incremental channel quality values to the contents of the register; and

resetting the register with the full channel quality value when the full channel value is received.

3. The apparatus of claim 1, wherein the full channel value is received concurrently with more than one incremental channel quality value.

6. The apparatus of claim 1, wherein scheduling forward link transmissions comprises packaging data on the forward link channel in multiple redundant subpackets.

4. A method for estimating forward link channel quality from a full channel quality value and a plurality of incremental channel quality values, comprising:

decoding the full channel quality value over a plurality of slots of a channel quality indicator channel (CQICH);

incrementally updating a channel state register with the plurality of incremental channel quality values, wherein each of the plurality of incremental channel quality values are received separately over each of the plurality of slots of the CQICH;

resetting the channel state register with the full channel quality value when the full channel quality value is fully decoded;

determining forward link channel power level and data transmission rate in accordance with the channel state register; and

scheduling forward link transmissions in accordance with the channel state register.

7. The method of claim 4, wherein scheduling forward link transmissions comprises packaging data on the forward link channel in multiple redundant subpackets.

5. Apparatus for estimating forward link channel quality from a full channel quality value and a plurality of incremental channel quality values, comprising:

means for decoding the full channel quality value over a plurality of slots of a channel quality indicator channel (CQICH);

means for incrementally updating a channel state register with the plurality of incremental channel quality values, wherein each of the plurality of incremental channel quality values are received separately over each of the plurality of slots of the CQICH and for resetting the channel state register with the full channel quality value when the full channel quality value is fully decoded;

means for determining forward link channel power level and data transmission rate in accordance with the channel state register; and

means for scheduling forward link channel transmissions in accordance with the updated register.

8. The apparatus of claim 5, wherein the means for scheduling forward link transmissions further packages data on the forward link channel in multiple redundant subpackets.