Approach for determining signal to noise ratios based on equalizer outputs and managing power for communications channels based on performance

• US 7,532,868 B1
• Filed: 10/25/2005
• Issued: 05/12/2009
• Est. Priority Date: 04/27/2001
• Status: Expired due to Term

• Current Assignee: Bandspeed, LLC
• Original Assignee: Bandspeed, Inc. (Broadcom, Inc.)
• Inventors: Skafidas, Efstratios, Treister, Bijan, Gan, Hongbing, Sapozhnykov, Vitaliy, Xiang, Yong
• Primary Examiner(s): Kincaid, Lester
• Assistant Examiner(s): DOAN, PHUOC HUU
• Application Number:
  US11/258,633
• Time in Patent Office: 1,295 Days
• Field of Search: None
• US Class Current: 455/127.1
• CPC Class Codes: H04W 52/24 using SIR [Signal to Interference Ratio] or other wireless path parameters

Abstract

A novel approach for determining signal to noise ratios based on equalizer outputs and managing power for a plurality of communications channels based on communications channel performance is disclosed. According to one aspect of the invention, a noise power is generated based on an error output of an equalizer that receives input from a communications channel, and a signal power is generated based on a signal output of the equalizer. A signal to noise ratio is determined based on the noise power and the signal power. According to another aspect of the invention, a first power and a second power that is different than the first power are determined based on performance data for the plurality of communications channels. The first power is used for communications that use a first communications channel, and the second power is used for communications that use a second communications channel.

Claims

1. A method for managing power for a plurality of communications channels based on performance in a frequency hopping communications system that includes at least a master participant and a slave participant, the method comprising the computer-implemented steps of:

(a) the master participant receiving from the slave participant a first communication over a communications channel of the plurality of communications channels;

(b) processing the first communication using an equalizer that is associated with the master participant;

(c) based on processing the first communication using the equalizer, determining an estimated signal to noise ratio;

(d) based on a comparison of the estimated signal to noise ratio to a specified signal to noise ratio, determining a power to be used to transmit from the slave participant to the master participant over the communications channel;

(e) the master participant sending a second communication to the slave participant, wherein the second communication specifies the power to be used to transmit form the slave participant to the master participant over the communications channel;

(f) the master participant receiving from the slave participant a third communication over the communications channel, wherein the third communication is based on the power specified in the second communication;

(g) repeating steps (a) through (f) for at least a second communications channel of the plurality of communications channels, wherein the second communications channel is between the master participant and the slave participant.

2. The method of claim 1, wherein determining the estimated signal to noise ratio, based on processing the first communication using the equalizer, further comprises the computer-implemented steps of:

generating a noise power, based on an error output of the equalizer that receives input from the communications channel;

generating a signal power, based on a signal output of the equalizer; and

determining the estimated signal to noise ratio, based on the noise power and the signal power.

3. The method of claim 1, wherein the step of determining the power includes the computer-implemented steps of:

determining an initial power based on the comparison of the estimated signal to noise ratio and the specified signal to noise ratio;

determining whether the initial power satisfies one or more criteria;

when the initial power satisfies the one or more criteria, determining the change in the power based on the initial power;

when the initial power fails to satisfy the one or more criteria;

generating a modified power; and

using the modified power as the power to be used to transmit from the slave participant to the master participant over the communications channel.

4. The method of claim 3, wherein the one or more criteria include a minimum power, wherein the initial power is less than the minimum power, and the step of determining the power further includes the computer-implemented steps of:

generating the modified power based on the minimum power; and

using the modified power as the power to be used to transmit from the slave participant to the master participant over the communications channel.

5. The method of claim 3, wherein the one or more criteria include a maximum power, wherein the initial power is greater than the maximum power, and the step of determining the power further includes the computer-implemented steps of:

generating the modified power based on the maximum power; and

using the modified power as the power to be used to transmit from the slave participant to the master participant over the communications channel.

6. The method of claim 5, wherein performance of the communications channel based on the power fails to satisfy one or more channel performance criteria, and the step of determining the power further includes the computer-implemented step of:

reducing the power to less than the maximum power.

7. The method of claim 6, wherein the power is a first power, and wherein the step of reducing the power to less than the maximum power includes the computer-implemented step of:

reducing the first power to a particular power that is selected from the group consisting of a second power that is less than a minimum power and a third power that is about zero power.

8. A computer-readable medium carrying one or more sequences of instructions for managing power for a plurality of communications channels based on performance in a frequency hopping communications system that includes at least a master participant and a slave participant, wherein execution of the one or more sequences of instructions by one or more processors causes the one or more processors to perform the steps of:

(a) the master participant receiving from the slave participant a first communication over a communications channel of the plurality of communications channel;

(b) processing the first communication using an equalizer that is associated with the master participant;

(c) based on processing the first communication using the equalizer, determining an estimated signal to noise ratio;

(d) based on a comparison of the estimated signal to noise ratio to a specified signal to noise ratio, determining a power to be used to transmit from the slave participant to the master participant over the communications channel;

(e) the master participant sending a second communication to the slave participant, wherein the second communication specifies the power to be used to transmit form the slave participant to the master participant over the communications channel;

(f) the master participant receiving from the slave participant a third communication over the communications channel, wherein the third communication is based on the power specified in the second communication;

(g) repeating steps (a) through (f) for at least a second communications channel of the plurality of communications channels, wherein the second communications channel is between the master participant and the slave participant.

9. The computer-readable medium of claim 8, wherein the instructions for determining the estimated signal to noise ratio, based on processing the first communication using the equalizer, include one or more sequences of instructions which, when executed by the one or more processors, causes the one or more processors to perform the steps of:

generating a noise power, based on an error output of the equalizer that receives input from the communications channel;

generating a signal power, based on a signal output of the equalizer; and

determining the estimated signal to noise ratio, based on the noise power and the signal power.

10. The computer-readable medium of claim 8, wherein the instructions for determining the power include one or more sequences of instructions which, when executed by the one or more processors, causes the one or more processors to perform the steps of:

determining an initial power based on the comparison of the estimated signal to noise ratio and the specified signal to noise ratio;

determining whether the initial power satisfies one or more criteria;

when the initial power satisfies the one or more criteria, determining the change in the power based on the initial power;

when the initial power fails to satisfy the one or more criteria;

generating a modified power; and

determining the change in the power based on the modified power.

11. The computer-readable medium of claim 10, wherein the one or more criteria include a minimum power, wherein the initial power is less than the minimum power, the instructions for determining the power further include one or more sequences instructions which, when executed by the one or more processors, causes the one or more processors to perform the steps of:

generating the modified power based on the minimum power; and

using the modified power as the power to be used to transmit from the slave participant to the master participant over the communications channel.

12. The computer-readable medium of claim 10, wherein the one or more criteria include a maximum power, wherein the initial power is greater than the maximum power, and the instructions for determining the power further include one or more sequences of instructions which, when executed by the one or more processors, causes the one or more processors to perform the steps of:

generating the modified power based on the maximum power; and

using the modified power as the power to be used to transmit from the slave participant to the master participant over the communications channel.

13. The computer-readable medium of claim 12, wherein performance of the communications channel based on the power fails to satisfy one or more channel performance criteria, and the instructions for determining the power further include one or more sequences of instructions which, when executed by the one or more processors, causes the one or more processors to perform the step of:

reducing the power to less than the maximum power.

14. The computer-readable medium of claim 13, wherein the power is a first power, and wherein the instructions for reducing the power to less than the maximum power include one or more sequences of instructions which, when executed by the one or more processors, causes the one or more processors to perform the steps of:

reducing the first power to a particular power that is selected from the group consisting of a second power that is less than a minimum power and a third power that is about zero power.