Relayed communication with versatile self-interference cancellation

• US 20050190870A1
• Filed: 03/25/2005
• Published: 09/01/2005
• Est. Priority Date: 08/08/2001
• Status: Active Grant

• Current Assignee: ViaSat Incorporated
• Original Assignee: ViaSat Incorporated
• Inventors: Murphy, James, Miller, Mark, Blount, Richard
• Granted Patent: US 7,349,505 B2
• Time in Patent Office: Days
• US Class Current: 375/346
• CPC Class Codes: H04B 1/525 with means for reducing leakage of transmitter signal into the receiver
• CPC Class Codes: H04B 7/15585 by interference cancellation
• CPC Class Codes: H04B 7/2606 Arrangements for base station coverage control, e.g. by using relays in tunnels

Abstract

Methods, apparatuses, and systems are presented for providing self-interference cancellation in two-way relayed electromagnetic communication between a first and a second device through a relay station, involving retrofitting existing equipment comprising a transmitter system and a receiver system at the first device by adding a canceler module, providing a version of a modulated near signal as a first non-baseband interface signal from the transmitter system to the canceler module, providing a version of a composite signal as a second non-baseband interface signal from the receiver system to the canceler module, generating a cancellation signal at the canceler module corresponding to a relayed version of the modulated near signal, using the first and the second non-baseband interface signals, applying the cancellation signal at the canceler module to a version of the second non-baseband interface signal, to produce a cancellation-processed signal as a third non-baseband interface signal provided to the receiver system.

Claims

1. A method for providing self-interference cancellation in two-way relayed electromagnetic communication between a first device and a second device through a relay station, the first device being capable of transmitting a modulated near signal and receiving a composite signal containing a relayed version of the modulated near signal a relayed version of a modulated far signal transmitted from the second device, the method comprising the steps of:

retrofitting existing equipment at the first device by adding a canceler module, wherein the existing equipment comprises a transmitter system and a receiver system;

providing a version of the modulated near signal as a first non-baseband interface signal from the transmitter system to the canceler module;

providing a version of the composite signal as a second non-baseband interface signal from the receiver system to the canceler module;

at the canceler module, generating a cancellation signal corresponding to the relayed version of the modulated near signal, using the first non-baseband interface signal and the second non-baseband interface signal;

at the canceler module, applying the cancellation signal to a version of the second non-baseband interface signal, to produce a cancellation-processed signal as a third non-baseband interface signal from the canceler module; and

providing the cancellation-processed signal to the receiver system.

2. The method of claim 1 wherein the first non-baseband interface signal is provided from the transmitter system by tapping the transmitter system at a signal connector.

3. The method of claim 1 wherein the second non-baseband interface signal is provided from the receiver system by tapping the receiver system at a signal connector.

4. The method of claim 1 wherein the third non-baseband interface signal is provided to the receiver system at a signal connector.

5. The method of claim 1 wherein the first non-baseband interface signal, second non-baseband interface signal, and third non-baseband interface signal are interface frequency (IF) signals.

6. The method of claim 1 wherein the first non-baseband interface signal, second non-baseband interface signal, and third non-baseband interface signal are radio frequency (RF) signals.

7. The method of claim 1 wherein the generated cancellation signal takes into account distortions introduced by the transmit system.

8. The method of claim 1 wherein the canceler module generates a time-delayed and phase-rotated signal in producing the cancellation signal.

9. The method of claim 8 wherein the canceler module adaptively filters the time-delayed and phase-rotated signal to produce the cancellation signal.

10. The method of claim 9 wherein the caceler module utilizes the cancellation-processed signal as a feedback signal to adaptively filter the time-delayed and phase rotated signal.

11. An apparatus for providing self-interference cancellation in two-way relayed electromagnetic communication between a first device and a second device through a relay station, the first device being capable of transmitting a modulated near signal and receiving a composite signal containing a relayed version of the modulated near signal a relayed version of a modulated far signal transmitted from the second device, the apparatus comprising:

a canceler module capable of being added to existing equipment at the first device to retrofit the existing equipment, the existing equipment comprising a transmitter system and a receiver system;

wherein the transmitter system is capable of providing a version of the modulated near signal as a first non-baseband interface signal to the canceler module;

wherein the receiver system is capable of providing a version of the composite signal as a second non-baseband interface signal to the canceler module;

wherein the canceler module is adapted to generate a cancellation signal corresponding to the relayed version of the modulated near signal, using the first non-baseband interface signal and the second non-baseband interface signal;

wherein the canceler module is further adapted to apply the cancellation signal to a version of the second non-baseband interface signal, to produce a cancellation-processed signal as a third non-baseband interface signal from the canceler module; and

wherein the canceler module is capable of providing the cancellation-processed signal to the receiver system.

12. The apparatus of claim 11 wherein the transmitter system is capable of being tapped at a signal connector to provide the first non-baseband interface signal.

13. The apparatus of claim 11 wherein the receiver system is capable of being tapped at a signal connector to provide the second non-baseband interface signal.

14. The apparatus of claim 11 wherein the receiver system is capable of receiving the third non-baseband interface signal at a signal connector.

15. The apparatus of claim 11 wherein the first non-baseband interface signal, second non-baseband interface signal, and third non-baseband interface signal are interface frequency (IF) signals.

16. The apparatus of claim 11 wherein the first non-baseband interface signal, second non-baseband interface signal, and third non-baseband interface signal are radio frequency (RF) signals.

17. The apparatus of claim 11 wherein the generated cancellation signal takes into account distortions introduced by the transmit system.

18. The apparatus of claim 11 wherein the canceler module is adapted to generate a time-delayed and phase-rotated signal in producing the cancellation signal.

19. The apparatus of claim 18 wherein the canceler module is capable of adaptively filtering the time-delayed and phase-rotated signal to produce the cancellation signal.

20. The apparatus of claim 19 wherein the caceler module is capable of utilizing the cancellation-processed signal as a feedback signal to adaptively filter the time-delayed and phase rotated signal.

21. A system for providing self-interference cancellation in two-way relayed electromagnetic communication between a first device and a second device through a relay station, the first device being capable of transmitting a modulated near signal and receiving a composite signal containing a relayed version of the modulated near signal a relayed version of a modulated far signal transmitted from the second device, the method comprising the steps of:

means for retrofitting existing equipment at the first device by adding a canceler module, wherein the existing equipment comprises a transmitter system and a receiver system;

means for providing a version of the modulated near signal as a first non-baseband interface signal from the transmitter system to the canceler module;

means for providing a version of the composite signal as a second non-baseband interface signal from the receiver system to the canceler module;

means for, at the canceler module, generating a cancellation signal corresponding to the relayed version of the modulated near signal, using the first non-baseband interface signal and the second non-baseband interface signal;

means for, at the canceler module, applying the cancellation signal to a version of the second non-baseband interface signal, to produce a cancellation-processed signal as a third non-baseband interface signal from the canceler module; and

means for providing the cancellation-processed signal to the receiver system.