Channel quality feedback mechanism and method

• US 7,548,728 B2
• Filed: 03/15/2005
• Issued: 06/16/2009
• 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:
  US11/081,330
• Publication Number:
  US 20050180450A1
• Time in Patent Office: 1,554 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, 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, 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; and

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, and 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;

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

summing a portion of the plurality of incremental channel quality values; and

adding the summed portion of the plurality of incremental channel quality values to the full channel quality value set in the register; and

scheduling forward link transmissions in accordance with the updated register.

2. 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;

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;

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

summing a portion of the plurality of incremental channel quality values; and

adding the summed portion of the plurality of incremental channel quality values to the full channel quality value stored in the channel state register.

3. 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;

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;

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

summing the plurality of incremental channel quality values; and

adding the summed plurality of incremental channel quality values to the full channel quality value stored in the channel state register.

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;

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; and

resetting the channel state register with the full channel quality value when the full channel quality value is fully decoded, wherein if the full channel quality value cannot be decoded, then using the plurality of incremental channel quality values as the forward link channel quality.