Method and apparatus for controlling transmission power in a potentially transmission gated or capped communication system

• US 20020064135A1
• Filed: 01/22/2002
• Published: 05/30/2002
• Est. Priority Date: 01/28/1999
• Status: Active Grant

• Current Assignee: Charles E. Wheatley III, Fuyun Ling, Jack M. Holtzman, Keith Saints, Nagabhushana Sindhushayana, Tao Chen
• Original Assignee: Charles E. Wheatley III, Fuyun Ling, Jack M. Holtzman, Keith Saints, Nagabhushana Sindhushayana, Tao Chen
• Inventors: Wheatley, Charles E. III, Chen, Tao, Ling, Fuyun, Sindhushayana, Nagabhushana, Holtzman, Jack M., Saints, Keith
• Granted Patent: US 6,950,406 B2
• Time in Patent Office: Days
• US Class Current: 370/252
• CPC Class Codes: H04W 52/08 Closed loop power control
• CPC Class Codes: H04W 52/12 Outer and inner loops
• CPC Class Codes: H04W 52/20 using error rate
• CPC Class Codes: H04W 52/44 in connection with interruption of transmission

Abstract

A power control system for controlling the transmission power in a system wherein the transmission power may be gated or capped. The receiver employs a combination of closed loop and outer loop power control. The outer loop is frozen upon detection by the receiver that the signal has been capped or gated.

Claims

1. An apparatus for controlling the transmission energy of signals received from a remote transmitter, comprising:

receiver for measuring an energy of the signals to produce an energy indication; and

power control processor for generating a signal quality metric based on said measuring, generating closed loop power control commands in accordance with a comparison between the signal quality metric and a variable threshold, making a determination that the remote transmitter is not responding to the power control commands in a predetermined fashion, and suspending an updating of the variable threshold in accordance with said determination.

2. The apparatus of claim 1 wherein said signal quality metric is a signal to interference ratio, and wherein said power control processor comprises a signal to interference ratio computation element for generating said signal to interference ratio based on the energy indication.

3. The apparatus of claim 1 further comprising a demodulator for demodulating the signals and measuring demodulated symbol energies from symbols residing in said signals, and providing said demodulated symbol energies to said power control processor, wherein said power control processor generates said signal quality metric based on said demodulated symbol energies.

4. The apparatus of claim 1 further comprising a decoder for decoding frames residing in said signals and generating frame error information, and providing said frame error information to said power control processor, and wherein said power control processor makes said determination based on said frame error information.

5. The apparatus of claim 1 further comprising a decoder for decoding frames residing in said signals and generating a decoder metric, and providing said decoder metric to said power control processor, and wherein said power control processor makes said determination based on said decoder metric.

6. The apparatus of claim 1 further comprising a decoder for decoding frames residing in said signals and generating a decoder metric and frame error information, and providing said decoder metric and frame error information to said power control processor, and wherein said power control processor makes said determination based on said decoder metric and frame error information.

7. A method of controlling a transmission energy of signals received from a remote transmitter, comprising:

measuring an energy of the signals to produce an energy indication;

generating a signal quality metric based on said measuring;

generating closed loop power control commands in accordance with a comparison between the signal quality metric and a variable threshold;

making a determination that the remote transmitter is not responding to the power control commands in a predetermined fashion; and

suspending an updating of the variable threshold in accordance with said determination.

8. The method of claim 7 wherein said signal quality metric is a signal to interference ratio.

9. The method of claim 7 further comprising demodulating symbols residing in the signals to produce symbol energies, wherein said generating said signal quality metric is based on said demodulated symbol energies.

10. The method of claim 7 further comprising decoding frames residing in the signals to produce frame error information, wherein said making a determination is based on said frame error information.

11. The method of claim 7 further comprising decoding frames residing in the signals to produce a decoder metric, wherein said making a determination is based on said decoder metric.

12. The method of claim 7 further comprising decoding frames residing in the signals to produce a decoder metric and frame error information, wherein said making a determination is based on said decoder metric and frame error information.

13. The method of claim 7 wherein said making a determination comprises detecting a gating of the transmission energy of the signals based on said energy indication.

14. The method of claim 7 wherein said making a determination comprises recognizing an absence of increase in said energy indication in response to at least one of said closed loop power control commands.