Innovative combinational closed-loop and open-loop satellite user terminal power control system

• US 20060203921A1
• Filed: 03/10/2005
• Published: 09/14/2006
• Est. Priority Date: 03/10/2005
• Status: Active Grant

• Current Assignee: The Boeing Co.
• Original Assignee: The Boeing Co.
• Inventors: Wang, Weizheng W., Chang, Anchung, Feria, Ying J.
• Granted Patent: US 7,599,659 B2
• Time in Patent Office: Days
• US Class Current: 375/242
• CPC Class Codes: H04B 7/18543 for adaptation of transmission parameters, e.g. power control for detecting or preventing errors in the information received H04L1/00
• CPC Class Codes: H04W 52/06 TPC algorithms
• CPC Class Codes: H04W 52/08 Closed loop power control
• CPC Class Codes: H04W 52/10 Open loop power control
• CPC Class Codes: H04W 52/146 Uplink power control
• CPC Class Codes: H04W 52/223 predicting future states of the transmission
• CPC Class Codes: H04W 52/241 taking into account channel quality metrics, e.g. SIR, SNR, CIR, Eb/lo
• CPC Class Codes: H04W 52/243 taking into account interferences

Abstract

Devices and methods are disclosed for reducing power control cushion of a user terminal configured to communicate with a satellite and a gateway station. The present invention provides a power control algorithm implemented in a user terminal that is designed to operate in a satellite communication system. The power control algorithm can recursively calculate a returnlink power to reduce a power control cushion so that an extra link margin is available to the satellite communication system. The present invention also provides a source coding technique that provides an accurate feedback signal for the user terminal. The average metric of input signal frames is coded in a sequence of bits that are carried by contiguous output signal frames.

Claims

1. A method for coding an average metric value of a plurality of input signal frames, comprising:

receiving a plurality of input signal frames;

decoding the plurality of input signal frames;

calculating a plurality of metrics using the plurality of input signal frames;

calculating an average metric of the plurality of metrics;

selecting a sequence of bits comprising a plurality of synchronization bits and a set of information bits;

populating the sequence of bits, the set of information bits corresponding to the average metric; and

sending the sequence of bits using a plurality of output signal frames.

2. The method of claim 1, wherein the step of populating the sequence comprises:

assigning ones to the plurality of synchronization bits.

3. The method of claim 1, wherein the plurality of synchronization bits includes two bits and the set of information bits includes three bits.

4. The method of claim 1, wherein each of the plurality of output signal frames has one bit to carry one of the sequence of bits.

5. A method for coding an average metric value of a plurality of input signal frames, comprising:

receiving a plurality of input signal frames;

decoding the plurality of input signal frames;

calculating a plurality of metrics using the plurality of input signal frames;

calculating an average metric of the plurality of metrics;

coding the average metric; and

sending the average metric using a plurality of output signal frames.

6. The method of claim 5, wherein the step of coding comprises:

selecting a sequence of bits comprising a plurality of synchronization bits and a set of information bits;

assigning ones to the plurality of synchronization bits; and

populating the set of information bits in accordance with the average metric.

7. The method of claim 6, wherein the plurality of synchronization bits includes two bits and the set of information bits includes three bits, and wherein each of the plurality of output signal frames has one bit to carry one of the sequence of bits.

8. A method for coding an average metric value of a plurality of input signal frames, comprising:

receiving a plurality of input signal frames;

decoding the plurality of input signal frames;

calculating a plurality of metrics using the plurality of input signal frames;

calculating an average metric of the plurality of metrics;

selecting a sequence of bits comprising a plurality of synchronization bits and a set of information bits;

assigning ones to the plurality of synchronization bits;

populating the set of information bits in accordance with the average metric; and

sending the sequence of bits using a plurality of output signal frame.

9. A computer readable medium embodying program code with instructions for coding an average metric value of a plurality of input signal frames, said computer readable medium comprising:

program code for receiving a plurality of input signal frames;

program code for decoding the plurality of input signal frames;

program code for calculating a plurality of metrics using the plurality of input signal frames;

program code for calculating an average metric of the plurality of metrics;

program code for selecting a sequence of bits comprising a plurality of synchronization bits and a set of information bits;

program code for populating the sequence of bits, the set of information bits corresponding to the average metric; and

program code for sending the sequence of bits using a plurality of output signal frames.

10. The computer readable medium of claim 9, wherein said computer readable medium comprises:

program code for assigning ones to the plurality of synchronization bits.

11. The computer readable medium of claim 9, wherein the plurality of synchronization bits includes two bits and the set of information bits includes three bits.

12. The computer readable medium of claim 9, wherein each of the plurality of output signal frames has one bit to carry one of the populated sequence of bits.

13. The computer readable medium of claim 9, wherein said computer readable medium is implemented in a gateway station.

14. A method for controlling a returnlink power of a user terminal, said method comprising:

receiving a broadcasting-signal-to-noise-ratio;

estimating a forwardlink carrier-signal-to-noise-ratio based on the broadcasting-signal-to-noise-ratio;

predicting a forwardlink degradation based on the forwardlink carrier-signal-to-noise-ratio;

receiving an error of a returnlink signal;

estimating a returnlink carrier-signal-to-noise-ratio based on the error;

predicting a noise and interference of the returnlink signal; and

calculating a returnlink power signal based on the forwardlink degradation, noise and interference.

15. The method of claim 14, further comprising:

using the returnlink power signal in the steps of estimating a returnlink carrier-signal-to-noise-ratio, predicting a forwardlink degradation, and predicting a noise and interference.

16. The method of claim 14, further comprising:

estimating a set of model parameters to adjust the noise, interference, and a dynamic degradation.

17. The method of claim 16, wherein the step of estimating a set of model parameters is based on a Kalman filter.

18. The method of claim 14, wherein the user terminal is a cellular phone or a personal digital assistant.

19. A method for controlling a returnlink power of a user terminal, said method comprising:

receiving a broadcasting-signal-to-noise-ratio;

estimating a forwardlink carrier-signal-to-noise-ratio based on the broadcasting-signal-to-noise-ratio;

predicting a forwardlink degradation based on the forwardlink carrier-signal-to-noise-ratio;

calculating adaptively a correlation between a variation of forwardlink signal and a variation of the returnlink signal using a delayed feedback measurement.

receiving an error of a returnlink signal;

estimating a returnlink carrier-signal-to-noise-ratio based on the error;

predicting a noise and interference of the returnlink signal;

calculating a returnlink power signal based on the forwardlink degradation, noise and interference;

using the returnlink power signal in the steps of estimating a returnlink carrier-signal-to-noise-ratio, predicting a forwardlink degradation, and predicting a noise and interference; and

estimating a set of model parameters to adjust the noise, interference, and a dynamic degradation based on a Kalman filter.

20. The method of claim 19, wherein the user terminal is a cellular phone or a personal digital assistant.

21. A computer readable medium embodying program code with instructions for controlling a returnlink power, said computer readable medium comprising:

program code for receiving a broadcasting-signal-to-noise-ratio;

program code for estimating a forwardlink carrier-signal-to-noise-ratio based on the broadcasting-signal-to-noise-ratio;

program code for predicting a variation of forwardlink degradation based on a variation of the forwardlink carrier-signal-to-noise-ratio;

program code for receiving an error of a returnlink signal;

program code for estimating a returnlink carrier-signal-to-noise-ratio based on the error;

program code for predicting a noise and interference of the returnlink signal; and

program code for calculating a returnlink power signal based on the forwardlink degradation, noise and interference.

22. The computer readable medium of claim 21, wherein said computer readable medium comprises program code for using the returnlink power signal in a process of executing the program codes for estimating a returnlink carrier-signal-to-noise-ratio, predicting a forwardlink degradation, and predicting a noise and interference.

23. The computer readable medium of claim 21, wherein said computer readable medium comprises program code for estimating a set of model parameters to adjust the noise, interference, and a dynamic degradation.

24. The computer readable medium of claim 21, wherein the program code for estimating a set of model parameters is based on a Kalman filter.

25. The computer readable medium of claim 21, wherein the user terminal is a cellular phone or a personal digital assistant.

26. A satellite communication system, comprising:

a satellite; and

at least one user terminal comprising;

a forwardlink receiver configured to receive a forwardlink broadcasting signal and a forwardlink user-data transmission signal from the satellite;

a returnlink power control configured to generate a returnlink power signal based on the forwardlink broadcasting signal and the forwardlink user-data transmission signal; and

a returnlink transmission configured to send the returnlink power signal to the satellite.

27. The satellite communication system of claim 26, further comprising a gateway station configured to communicate with the satellite, said gateway station comprises:

a feederlink receiver configured to receive a signal from the satellite; and

a feederlink transmission configured to receive a metric and a pilot tune signal power from the feederlink receiver and send a signal to the satellite.

28. The satellite communication system of claim 26, wherein the at least one user terminal communicates with the satellite via a channel having a static degradation mechanism and a dynamic degradation mechanism.

29. The satellite communication system of claim 28, wherein the static degradation mechanism is in out-space region.

30. The satellite communication system of claim 28, wherein the dynamic degradation mechanism is in atmosphere.

31. The satellite communication system of claim 26, wherein the at least one user terminal is a cellular phone or a personal digital assistant.

32. A satellite communication system, comprising:

a satellite;

at least one user terminal configured to communicate with the satellite via a channel, said at least one user terminal comprising;

a forwardlink receiver configured to receive a forwardlink broadcasting signal and a forwardlink user-data transmission signal from the satellite;

a returnlink power control configured to generate a returnlink power signal based on the forwardlink broadcasting signal and the forwardlink user-data transmission signal; and

a returnlink transmission configured to send the returnlink power signal to the satellite; and

a gateway station configured to communicate with the satellite comprising;

a feederlink receiver configured to receive a signal from the satellite; and

a feederlink transmission configured to receive a metric and a pilot tune signal power from the feederlink receiver and send a signal to the satellite.

33. A method for controlling a returnlink power of a user terminal, said method comprising:

receiving a returnlink error and a returnlink power;

estimating a returnlink carrier-signal-to-noise-ratio based on the returnlink error and returnlink power;

predicting a noise and interference of the returnlink power based on the returnlink carrier-signal-to-noise-ratio and the returnlink power;

receiving a forwardlink power;

estimating a forwardlink carrier-signal-to-noise-ratio based on the forwardlink power;

calculating adaptively a correlation between a variation of the forwardlink power and a variation of the returnlink power;

predicting a forwardlink degradation based on the forwardlink carrier-signal-to-noise-ratio, the correlation and the returnlink power; and

computing a returnlink power based on the noise, the interference and the forwardlink degradation.

34. The method of claim 33, further comprising:

estimating a set of model parameters to adjust the noise, the interference, and a dynamic degradation based on a Kalman filter.

35. The method of claim 33, wherein the user terminal is a cellular phone or a personal digital assistant.

36. A computer readable medium embodying program code with instructions for controlling a returnlink power, said computer readable medium comprising:

program code for receiving a returnlink error and a returnlink power;

program code for estimating a returnlink carrier-signal-to-noise-ratio based on the returnlink error and returnlink power;

program code for predicting a noise and interference of the returnlink power based on the returnlink carrier-signal-to-noise-ratio and the returnlink power;

program code for receiving a forwardlink power;

program code for estimating a forwardlink carrier-signal-to-noise-ratio based on the forwardlink power;

program code for calculating adaptively a correlation between a variation of the forwardlink power and a variation of the returnlink power;

program code for predicting a forwardlink degradation based on the forwardlink carrier-signal-to-noise-ratio, the correlation and the returnlink power; and

program code for computing a returnlink power based on the noise, the interference and the forwardlink degradation.

37. The computer readable medium of claim 36, wherein said computer readable medium comprises program code for estimating a set of model parameters to adjust the noise, the interference, and a dynamic degradation.

38. The computer readable medium of claim 37, wherein the program code for estimating a set of model parameters is based on a Kalman filter.