Closed-loop rate control for a multi-channel communication system

• US 8,218,609 B2
• Filed: 05/31/2003
• Issued: 07/10/2012
• Est. Priority Date: 10/25/2002
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Walton, Jay Rodney, Wallace, Mark S., Ketchum, John W., Howard, Steven J.
• Primary Examiner(s): Bocure, Tesfaldet
• Application Number:
  US10/448,801
• Publication Number:
  US 20040120411A1
• Time in Patent Office: 3,328 Days
• Field of Search: 375/260, 375/295, 375/316, 375/347, 375/259, 375/322, 375/334, 375/346, 375/141, 375/221, 375/296, 375/267, 375/377, 375/340, 375/219, 375/358, 375/299, 375/337, 375/349, 375/350, 455/130, 370/208, 370/210
• US Class Current: 375/219
• CPC Class Codes: H04B 7/0417 Feedback systems
• CPC Class Codes: H04B 7/043 using best eigenmode, e.g. beam forming or beam steering
• CPC Class Codes: H04B 7/0443 utilizing "waterfilling" technique
• CPC Class Codes: H04B 7/0669 using different channel coding between antennas space-time coding H04L1/0618
• CPC Class Codes: H04B 7/0697 using spatial multiplexing
• CPC Class Codes: H04B 7/0854 using error minimizing algorithms, e.g. minimum mean squared error [MMSE], "cross-correlation" or matrix inversion
• CPC Class Codes: H04L 1/0002 by adapting the transmission rate
• CPC Class Codes: H04L 1/0003 by switching between different modulation schemes
• CPC Class Codes: H04L 1/0009 by adapting the channel coding H04L1/1812 takes precedence
• CPC Class Codes: H04L 1/0016 involving special memory structures, e.g. look-up tables
• CPC Class Codes: H04L 1/0017 where the mode-switching is based on Quality of Service requirement
• CPC Class Codes: H04L 1/0025 Transmission of mode-switching indication
• CPC Class Codes: H04L 1/0059 Convolutional codes
• CPC Class Codes: H04L 1/0061 Error detection codes
• CPC Class Codes: H04L 1/0071 Use of interleaving interleaving per se H03M13/27
• CPC Class Codes: H04L 1/0675 characterised by the signaling
• CPC Class Codes: H04L 1/20 using signal quality detector
• CPC Class Codes: H04L 2001/0093 Point-to-multipoint
• CPC Class Codes: H04L 25/0224 using sounding signals
• CPC Class Codes: H04L 25/0226 sounding signals per se
• CPC Class Codes: H04L 25/0242 : using matrix methods
• CPC Class Codes: H04L 25/03343 : Arrangements at the transmitter end
• CPC Class Codes: H04L 27/2601 : Multicarrier modulation systems
• CPC Class Codes: H04L 27/2602 : Signal structure
• CPC Class Codes: H04L 27/261 : Details of reference signals
• CPC Class Codes: H04L 27/2647 : Arrangements specific to the receiver only equalisation H04L27/01
• CPC Class Codes: H04W 16/28 : using beam steering
• CPC Class Codes: H04W 52/50 : at the moment of starting communication in a multiple access environment
• CPC Class Codes: Y02D 30/50 : in wire-line communication networks, e.g. low power modes or reduced link rate

Abstract

Closed-loop rate control for data transmission on multiple parallel channels is provided. An inner loop estimates the channel conditions for a communication link and selects a suitable data rate for each of the multiple parallel channels based on the channel estimates. For each parallel channel, a received SNR is computed based on the channel estimates, an operating SNR is computed based on the received SNR and an SNR offset for the parallel channel, and the data rate is selected based on the operating SNR for the parallel channel and a set of required SNRs for a set of data rates supported by the system. An outer loop estimates the quality of data transmissions received on the multiple parallel channels and adjusts the operation of the inner loop. For example, the SNR offset for each parallel channel is adjusted based on the status of packets received on that parallel channel.

Claims

1. A method of transmitting data on a plurality of parallel channels in a wireless communication system, comprising:

in a first processing loop, adjusting at least one adjustment parameter for each of a plurality of parallel channels based on errors detected in received packets;

in a second processing loop, determining channel estimates for each of the plurality of parallel channels, and selecting a transmission mode for each of the plurality of parallel channels based on an aggregation of the channel estimates and the at least one adjustment parameter for the parallel channel, wherein the selected transmission mode for each of the plurality of parallel channels determines a data rate for the parallel channel; and

sending the selected transmission mode for each of the plurality of parallel channels to a transmitting entity, wherein data for each of the plurality of parallel channels is processed at the transmitting entity in accordance with the transmission mode selected for that parallel channel, and is transmitted through each parallel channel at the data rate determined by the transmission mode selected for the parallel channel.

2. The method of claim 1, wherein the adjustment parameter includes at least one signal to noise ratio offset.

3. The method of claim 2, wherein adjusting the at least one adjustment parameter includes determining the at least one adjustment parameter based, at least in part, on detected packet errors.

4. The method of claim 1, wherein the channel estimates include at least one signal to noise ratio.

5. An apparatus for transmitting data on a plurality of parallel channels in a wireless communication system, comprising:

a means for performing a first processing loop to adjust at least one adjustment parameter for each of a plurality of parallel channels based on errors detected in received packets;

a means for performing a second processing loop to determine channel estimates for each of the plurality of parallel channels, and select a transmission mode for each of the plurality of parallel channels based on an aggregation of the channel estimates and the at least one adjustment parameter for the parallel channel, wherein the selected transmission mode for each of the plurality of parallel channels determines a data rate for the parallel channel; and

a means for sending the selected transmission mode for each of the plurality of parallel channels to a transmitting entity, wherein data for each of the plurality of parallel channels is processed at the transmitting entity in accordance with the transmission mode selected for the parallel channel, and is transmitted through each parallel channel at the data rate determined by the transmission mode selected for the parallel channel.

6. The apparatus of claim 5, wherein the adjustment parameter includes at least one signal to noise ratio offset.

7. The apparatus of claim 6, wherein the means for performing the first processing loop to adjust the at least one adjustment parameter is configured to adjust the at least one adjustment parameter based, at least in part, on detected packet errors.

8. The apparatus of claim 5, wherein the channel estimates include at least one signal to noise ratio.

9. A memory unit having instructions stored thereon for transmitting data on a plurality of parallel channels in a wireless communication system, the instructions, when executed by one or more processors, directing the one or more processors to perform the steps of:

performing a first processing loop to adjust at least one adjustment parameter for each of a plurality of parallel channels based on errors detected in received packets;

performing a second processing loop to determine channel estimates for each of the plurality of parallel channels, and select a transmission mode for each of the plurality of parallel channels based on an aggregation of the channel estimates and the at least one adjustment parameter for the parallel channel, wherein the selected transmission mode for each of the plurality of parallel channels determines a data rate for the parallel channel; and

sending the selected transmission mode for each of the plurality of parallel channels to a transmitting entity, wherein data for each of the plurality of parallel channels is processed at the transmitting entity in accordance with the transmission mode selected for the parallel channel, and is transmitted through each parallel channel at the data rate determined by the transmission mode selected for the parallel channel.

10. The memory unit of claim 9, wherein the adjustment parameter includes at least one signal to noise ratio offset.

11. The memory unit of claim 10, wherein the instructions for performing the first processing loop comprises instructions for adjusting the at least one adjustment parameter based, at least in part, on detected packet errors.

12. The memory unit of claim 9, wherein the channel estimates include at least one signal to noise ratio.

13. An apparatus for transmitting data on a plurality of parallel channels in a wireless communication system, comprising:

at least one processor configured to,

perform a first processing loop to adjust at least one adjustment parameter for each of a plurality of parallel channels based on errors detected in received packets; and

perform a second processing loop to determine channel estimates for each of the plurality of parallel channels, and select a transmission mode for each of the plurality of parallel channels based on an aggregation of the channel estimates and the at least one adjustment parameter for the parallel channel, wherein the selected transmission mode for each of the plurality of parallel channels determines a data rate for the parallel channel, and

send the selected transmission mode for each of the plurality of parallel channels to a transmitting entity, wherein data for each of the plurality of parallel channels is processed at the transmitting entity in accordance with the transmission mode selected for the parallel channel, and is transmitted through each parallel channel at the data rate determined by the transmission mode selected for the parallel channel; and

at least one memory coupled to the processor.

14. The apparatus of claim 13, wherein the adjustment parameter includes at least one signal to noise ratio offset.

15. The apparatus of claim 14, wherein the processor is configured to adjust the at least one adjustment parameter based, at least in part, on detected packet errors.

16. The apparatus of claim 13, wherein the channel estimates include at least one signal to noise ratio.