FEEDBACK OF CHANNEL QUALITY INFORMATION

• US 20070287487A1
• Filed: 06/12/2007
• Published: 12/13/2007
• Est. Priority Date: 02/21/2002
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Wei, Yongbin, Puig-Oses, David, Lundby, Stein
• Granted Patent: US 7,656,843 B2
• Time in Patent Office: Days
• US Class Current: 455/501
• CPC Class Codes: H04L 1/001 applied to control information
• CPC Class Codes: H04L 1/0026 Transmission of channel quality indication
• CPC Class Codes: H04L 1/08 by repeating transmission, e.g. Verdan system H04L1/1858 and H04L1/189 take precedence
• CPC Class Codes: H04W 28/22 Negotiating communication rate
• CPC Class Codes: H04W 72/21 in the uplink direction of a wireless link, i.e. towards the network
• CPC Class Codes: H04W 72/542 using measured or perceived quality

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, a carrier-to-interference (C/I) symbol is transmitted over multiple slots at a reduced rate, which increases the likelihood that the base station can decode said symbol. The reduced rate mode can be selectively triggered by a high velocity condition or other unfavorable channel condition. The C/I symbol is used to determine transmission formats, power levels, and data rates of forward link transmissions.

Claims

1. An apparatus for controlling the operation of a quality feedback channel in a wireless communication system, 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;

determining a channel quality value associated with a transmission channel;

determining a condition of the transmission channel;

if the transmission channel condition is favorable, then transmitting the channel quality value over one slot of the channel quality feedback channel; and

if the channel condition is not favorable, then transmitting the channel quality value over a plurality of slots of the channel quality feedback channel.

2. The apparatus of claim 1, wherein the condition of the transmission channel is based upon a velocity estimate.

3. The apparatus of claim 1, wherein the condition of the transmission channel is based upon a power level estimate.

4. The apparatus of claim 1, wherein the condition of the transmission channel is based upon whether a fast fade occurs in the transmission channel.

5. A method for improving the reception of a channel quality value, comprising:

determining whether the condition of a transmission channel is favorable;

if the condition of the transmission channel is favorable, then transmitting the channel quality value over one slot of a feedback channel; and

if the condition of the transmission channel is unfavorable, then transmitting the channel quality value over more than one slot of the feedback channel.

6. The method of claim 5, wherein transmitting the channel quality value over more than one slot of the feedback channel further comprises:

repeating the channel quality value over a frame of the feedback channel.

7. The method of claim 5, wherein the channel condition is unfavorable if a first station and a second station travel at a high velocity in relation to each other, wherein the first station originates the feedback channel and the second station originates the transmission channel.

8. A method for improving the reception of a channel quality value at a base station, comprising:

determining whether the condition of a feedback channel from a remote station is favorable;

if the condition of the channel is unfavorable, then transmitting a control signal to the remote station, wherein the control signal triggers a reduced rate mode for transmitting the channel quality value over a feedback channel from the remote station; and

if the condition of the channel is favorable, then allowing the remote station to control the transmission of the channel quality value over the feedback channel.

9. An apparatus for improving the reception of a channel quality value at a base station, comprising:

means for determining whether the condition of a feedback channel from a remote station is favorable;

means for transmitting a control signal to the remote station if the condition of the channel is unfavorable, wherein the control signal triggers a reduced rate mode for transmitting the channel quality value over a feedback channel from the remote station; and

if the condition of the channel is favorable, then allowing the remote station to control the transmission of the channel quality value over the feedback channel.