APPARATUS AND METHODS FOR POWER CONTROL IN SATELLITE COMMUNICATIONS SYSTEMS WITH SATELLITE-LINKED TERRESTRIAL STATIONS

• US 20100029269A1
• Filed: 10/14/2009
• Published: 02/04/2010
• Est. Priority Date: 11/02/2004
• Status: Active Grant

• Current Assignee: ATC Technology Corporation (FedEx Corporation)
• Original Assignee: ATC Technology Corporation (FedEx Corporation)
• Inventors: Karabinis, Peter D.
• Granted Patent: US 8,369,776 B2
• Time in Patent Office: Days
• US Class Current: 455/427
• CPC Class Codes: H04B 7/18513 Transmission in a satellite or space-based system
• 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: H04B 7/18563 Arrangements for interconnecting multiple systems data switching networks H04L12/00

Abstract

A signal power control loop is provided for a link between a terrestrial station and a terminal when the terminal and a satellite are linked via the terrestrial station. The signal power control loop may control transmitted signal power of the terminal and/or the terrestrial station. In some embodiments, the signal power control loop controls transmitted signal power of the terminal and/or the terrestrial station independent of signal power control for a link between the terrestrial station and the satellite.

Claims

1. A method of operating a satellite wireless communications system including a satellite configured to communicate with terminals directly and to communicate with terminals indirectly via a base station, the method comprising:

providing a first signal power control loop that controls transmitted signal power through a first communication link between the base station and a terminal; and

providing a second signal power control loop that controls transmitted signal power through a combination of the first communication link and a second communication link between the base station and the satellite concurrent with provision of the first signal power control loop.

2. A method according to claim 1, wherein the base station is configured on a vehicle.

3. A method according to claim 1, wherein the base station is distributed over a geographic region.

4. A method according to claim 1, wherein the base station is substantially localized at a specific geographic location.

5. A method according to claim 1, wherein the base station transmits information to a terminal using a polarization that is substantially orthogonal to a polarization used by another system.

6. A method according to claim 1, wherein the base station receives information from a terminal using at least two antenna elements that are substantially orthogonally polarized therebetween and/or are configured in a space diversity configuration.

7. A method according to claim 1, wherein the base station receives and/or transmits information in a Time Division Duplex (TDD) mode and/or via an antenna pattern that is responsive to a location of a terminal.

8. A method according to claim 1, further comprising providing a signal power control loop for a direct communication link between the terminal and the satellite when the terminal is in direct communication with the satellite.

9. A method according to claim 1, wherein the first signal power control loop controls transmitted signal power of the terminal and/or the base station.

10. A method according to claim 1, wherein the first signal power control loop controls transmitted signal power through the first communication link responsive to the second signal power control loop controlling transmitted signal power through the combination of the first communication link and the second communication link.

11. A method according to claim 1, wherein providing a first signal power control loop for a first communication link between the base station and a terminal comprises:

receiving a signal transmitted by the terminal at the base station;

generating power control information responsive to the received signal;

communicating the power control information to the terminal from the base station; and

controlling a transmitted signal power of the terminal responsive to the communicated power control information.

12. A method according to claim 11:

wherein generating power control information responsive to the received signal comprises generating a measure of received signal power;

wherein communicating the power control information to the terminal from the base station comprises communicating the measure of received signal power; and

wherein controlling a transmitted signal power of the terminal responsive to the communicated power control information comprises controlling a signal power of the terminal using the communicated measure of received signal power as a control feedback signal.

13. A method according to claim 12:

wherein generating power control information responsive to the received signal comprises generating a power command;

wherein communicating the power control information to the terminal from the base station comprises communicating the power command; and

wherein controlling a transmitted signal power of the terminal responsive to the communicated power control information comprises controlling a signal power of the terminal to conform to the communicated power command.

14. A method according to claim 1, wherein providing a first signal power control loop for a first communication link between the base station and a terminal comprises:

receiving a signal transmitted by the base station at the terminal;

generating power control information responsive to the received signal;

communicating the power control information to the base station from the terminal; and

controlling a transmitted signal power of the base station responsive to the communicated power control information.

15. A method according to claim 14:

wherein generating power control information responsive to the received signal comprises generating a measure of received signal power;

wherein communicating the power control information to the base station from the terminal comprises communicating the measure of received signal power; and

wherein controlling a transmitted signal power of the base station responsive to the communicated power control information comprises controlling a signal power of the base station using the communicated measure of received signal power as a control feedback signal.

16. A method according to claim 14:

wherein generating power control information responsive to the received signal comprises generating a power command;

wherein communicating the power control information to the base station from the terminal comprises communicating the power command; and

wherein controlling a transmitted signal power of the base station responsive to the communicated power control information comprises controlling the signal power of the base station to conform to the communicated power command,

17. A wireless communications system comprising:

a satellite configured to communicate with terminals directly and to communicate with terminals indirectly via a base station;

a first signal power control loop that controls transmitted signal power through a first communication link between the base station and a terminal when the terminal and the satellite are linked via the base station;

a second signal power control loop that controls transmitted signal power through a combination of the first communication link and a second communication link between the base station and the satellite concurrent with the first signal power control loop; and

a third signal power control loop that controls transmitted signal power through a third communication link between the terminal and the satellite when the terminal is in direct communication with the satellite.

18. A system according to claim 17, wherein the first signal power control loop controls transmitted signal power of the terminal and the base station.

19. A system according to claim 17, wherein the first control loop controls transmitted signal power through the first communication link responsive to the second signal power control loop controlling transmitted signal power through the combination of the first communication link and the second communication link.

20. A wireless communications system comprising:

a base station that is configured to communicate directly with a satellite, wherein the satellite is configured to communicate with terminals directly and to communicate with terminals indirectly via the base station;

a first signal power controller that operates a first power control loop that controls transmitted signal power through a first communication link between the base station and a terminal; and

a second signal power controller that operates a second signal power control loop that controls transmitted signal power through a combination of the first communication link and a second communication link between the base station and the satellite concurrent with operation of the first signal power control loop.

21. A system according to claim 20, wherein the first signal power controller is operative to control transmitted signal power of the terminal and/or of the base station.

22. A system according to claim 20, wherein the first signal power controller is responsive to the second signal power controller.

23. A system according to claim 20, wherein the base station comprises:

a first demodulation and regeneration unit configured to demodulate a signal received from the satellite and to regenerate the demodulated signal to produce a first regenerated signal;

a first modulator configured to modulate the first regenerated signal;

a first power amplifier configured to amplify the modulated first regenerated signal for transmission to the terminal;

a second demodulation and regeneration unit configured to demodulate a received signal from the terminal and to regenerate the demodulated signal to produce a second regenerated signal;

a second modulator configured to modulate the second regenerated signal;

a second power amplifier configured to amplify the modulated second regenerated signal for transmission to the satellite;

wherein the first demodulation and regeneration unit is operative to extract transmitted power control information from the signal received from the satellite and to control the second power amplifier responsive thereto; and

wherein the second demodulation and regeneration unit is operative to extract transmitted power control information from the signal received from the terminal and to control the first power amplifier responsive thereto.

24. A system according to claim 20, wherein the base station comprises:

a first demodulation and regeneration unit configured to demodulate a signal received from the satellite and to regenerate the demodulated signal to provide a first regenerated signal;

a first modulator configured to modulate the first regenerated signal;

a first power amplifier configured to amplify the modulated first regenerated signal for transmission to the terminal;

a second demodulation and regeneration unit configured to demodulate a received signal from the terminal and to regenerate the demodulated signal to provide a second regenerated signal;

a second modulator configured to modulate the second regenerated signal;

a second power amplifier configured to amplify the modulated second regenerated signal for transmission to the satellite;

wherein the first demodulation and regeneration unit is operative to determine received signal power for the signal received from the satellite and to provide power control information to the second demodulation and regeneration unit responsive thereto; and

wherein the second demodulation and regeneration unit is operative to determine received signal power for the signal received from the terminal and to provide power control information to the first demodulation and regeneration unit responsive thereto.

25. A system according to claim 20, wherein the first signal power controller is positioned at the base station.

26. A system according to claim 20, wherein the first signal power controller is positioned at the terminal.