OPTICALLY ENHANCED SELF-INTERFERENCE CANCELLATION

• US 20180375566A1
• Filed: 08/31/2018
• Published: 12/27/2018
• Est. Priority Date: 08/29/2013
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Kumu Networks, Inc.
• Inventors: Hong, Steven, Mehlman, Jeffrey, Brand, Joel, Choi, Jung-Il, Jain, Mayank
• Granted Patent: US 10,673,519 B2
• Time in Patent Office: Days
• CPC Class Codes: H04B 1/525 with means for reducing leakage of transmitter signal into the receiver
• CPC Class Codes: H04B 7/0413 MIMO systems
• CPC Class Codes: H04B 7/15585 by interference cancellation

Abstract

An optically-enhanced relay including a first transmitter that converts a first digital transmit signal to a first analog transmit signal, a first receiver that converts a first analog receive signal to a first digital receive signal, a second transmitter that converts a second digital transmit signal to a second analog transmit signal, a second receiver that converts a second analog receive signal to a second digital receive signal, and an optically-enhanced analog self-interference canceller that generates a first self-interference cancellation signal based on at least one of the first digital transmit signal and the first analog transmit signal, and combines the first self-interference cancellation signal with at least one of the first digital receive signal and the first analog receive signal.

Claims

1. An optically-enhanced relay comprising:

a first transmitter, coupled to a first signal path of the relay, that converts a first digital transmit signal received via the first signal path to a first analog transmit signal, and transmits the first analog transmit signal via the first signal path;

a first receiver, coupled to the first signal path of the relay, that receives a first analog receive signal via the first signal path, and converts the first analog receive signal to a first digital receive signal;

a second transmitter, coupled to a second signal path of the relay, that converts a second digital transmit signal received via the second signal path to a second analog transmit signal, and transmits the second analog transmit signal via the second signal path;

a second receiver, coupled to the second signal path of the relay, that receives a second analog receive signal via the second signal path, and converts the second analog receive signal to a second digital receive signal; and

an optically-enhanced analog self-interference canceller that generates a first self-interference cancellation signal based on at least one of the first digital transmit signal and the first analog transmit signal, and combines the first self-interference cancellation signal with at least one of the first digital receive signal and the first analog receive signal.

2. The optically-enhanced relay of claim 1, wherein the optically-enhanced analog self-interference canceller comprises an optical upconverter, communicatively coupled to the analog transmit signal, that converts the analog transmit signal to an optical transmit signal;

and a set of signal transformers that transform the optical transmit signal into optical self-interference cancellation signal components;

wherein the optically-enhanced analog self-interference canceller generates the first self-interference cancellation signal from the optical self-interference cancellation signal components.

3. The optically-enhanced relay of claim 2, wherein the optically-enhanced analog self-interference canceller further comprises an optical downconverter and a combining coupler;

wherein the optical downconverter converts the optical self-interference cancellation signal components to analog self-interference cancellation signal components;

wherein the combining coupler combines the analog self-interference cancellation signal components to form the first self-interference cancellation signal.

4. The optically-enhanced relay of claim 3, wherein the optically-enhanced analog self-interference canceller further comprises a sampling coupler;

wherein the sampling coupler splits the analog transmit signal into analog transmit signal components prior to optical upconversion;

wherein the optical upconverter converts the analog transmit signal components to optical transmit signal components;

wherein the set of signal transformers transforms the optical transmit signal by transforming the optical transmit signal components into optical self-interference cancellation signal components.

5. The optically-enhanced relay of claim 3, wherein the optically-enhanced analog self-interference canceller further comprises a sampling coupler;

wherein the sampling coupler splits the optical transmit signal into optical transmit signal components after optical upconversion;

wherein the set of signal transformers transforms the optical transmit signal by transforming the optical transmit signal components into optical self-interference cancellation signal components.

6. The optically-enhanced relay of claim 2, wherein the optically-enhanced analog self-interference canceller further comprises an optical downconverter and a combining coupler;

wherein the combining coupler combines the optical self-interference cancellation signal components to form an optical self-interference cancellation signal;

wherein the optical downconverter converts the optical self-interference cancellation signal to form the first self-interference cancellation signal.

7. The optically-enhanced relay of claim 4, wherein the optical downconverter comprises a photodetector circuit.

8. The optically-enhanced relay of claim 6, wherein the optically-enhanced analog self-interference canceller further comprises a sampling coupler;

wherein the sampling coupler splits the analog transmit signal into analog transmit signal components prior to optical upconversion;

wherein the optical upconverter converts the analog transmit signal components to optical transmit signal components;

wherein the set of signal transformers transforms the optical transmit signal by transforming the optical transmit signal components into optical self-interference cancellation signal components.

9. The optically-enhanced relay of claim 6, wherein the optically-enhanced analog self-interference canceller further comprises a sampling coupler;

wherein the sampling coupler splits the optical transmit signal into optical transmit signal components after optical upconversion;

wherein the set of signal transformers transforms the optical transmit signal by transforming the optical transmit signal components into optical self-interference cancellation signal components.

10. The optically-enhanced relay of claim 9, wherein the optical upconverter comprises a radio-frequency (RF) amplifier and a laser.

11. The optically-enhanced relay of claim 9, wherein the set of signal transformers generate the optical self-interference cancellation signal components by scaling and delaying the optical self-interference cancellation signal components.

12. The optically-enhanced relay of claim 11, wherein the set of signal transformers comprise both finite impulse response (FIR) and infinite impulse response (IIR) filters.

13. The optically-enhanced relay of claim 12, wherein the set of signal transformers are split into a set of parallel signal paths;

wherein each parallel signal path comprises one or more FIR filters in series with one or more IIR filters.

14. The optically-enhanced relay of claim 13, wherein the IIR filters of the optically-enhanced relay comprise a fiber-ring resonator.

15. The optically-enhanced relay of claim 14, wherein the fiber-ring resonator is a compound ring resonator.

16. The optically-enhanced relay of claim 14, wherein the fiber-ring resonator is part of a Side-Coupled Integrated Space Sequence of Resonators (SCISSOR) delayer.

17. The optically-enhanced relay of claim 14, wherein the fiber-ring resonator is part of a coupled resonator optical waveguide (CROW) delayer.

18. The optically-enhanced relay of claim 11, wherein the set of signal transformers comprises a switched-line delayer.

19. The optically-enhanced relay of claim 18, wherein the set of signal transformers comprises an optical amplifier.