Systems and methods for intelligently-tuned digital self-interference cancellation

• US 10,382,089 B2
• Filed: 09/07/2018
• Issued: 08/13/2019
• Est. Priority Date: 03/27/2017
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Kumu Networks, Inc.
• Inventors: Moorti, Rajendra Tushar, Viswanatha, Kumar
• Primary Examiner(s): Neff, Michael R
• Application Number:
  US16/125,269
• Publication Number:
  US 20190007089A1
• Time in Patent Office: 340 Days
• Field of Search: 375219
• CPC Class Codes: H04B 1/12 Neutralising, balancing, or compensation arrangements
• CPC Class Codes: H04B 1/123 using adaptive balancing or compensation means adaptive filter circuits and algorithms H03H
• CPC Class Codes: H04B 1/525 with means for reducing leakage of transmitter signal into the receiver
• CPC Class Codes: H04B 1/56 with provision for simultaneous communication in two directions
• CPC Class Codes: H04L 25/0202 Channel estimation
• CPC Class Codes: H04L 27/2647 Arrangements specific to the receiver only equalisation H04L27/01
• CPC Class Codes: H04L 5/14 Two-way operation using the same type of signal, i.e. duplex

Abstract

A system for digital self-interference cancellation includes a filter that generates a reduced-noise digital residue signal; a channel estimator that generates a current self-interference channel estimate from a digital transmit signal, the reduced-noise digital residue signal, and past self-interference channel estimates; a controller that dynamically sets the digital transform configuration in response to changes in a controller-sampled digital residue signal; and a channel memory that stores the past self-interference channel estimates.

Claims

1. A system for digital self-interference cancellation comprising:

a filter coupled to a digital residue signal of a communication system that reduces noise, thereby generating a first reduced-noise digital residue signal;

a channel estimator coupled to the filter that generates a current self-interference channel estimate from a sampled digital transmit signal, the first reduced-noise digital residue signal, and past self-interference channel estimates;

wherein the channel estimator generates the current self-interference channel estimate according to a digital transform configuration;

a controller that dynamically sets the digital transform configuration in response to changes in a controller-sampled digital residue signal; and

a channel memory, coupled to the channel estimator, that stores the past self-interference channel estimates;

wherein the system generates a digital self-interference cancellation signal from the current self-interference channel estimate and the sampled digital transmit signal;

wherein the digital self-interference cancellation signal is combined with a receive signal of the communication system to form the digital residue signal.

2. The system of claim 1, further comprising an analog self-interference canceller;

wherein the analog self-interference canceller generates, using an analog transmit signal of the communication system, an analog self-interference cancellation signal that is combined with the receive signal in analog;

wherein the digital self-interference cancellation signal is combined with the receive signal in digital after combination of the receive signal with the analog self-interference cancellation signal and after conversion of the receive signal from analog to digital.

3. The system of claim 2, wherein the sampled digital transmit signal is sampled from the analog transmit signal using an analog-to-digital converter;

wherein the analog transmit signal originates from a digital transmit signal converted from digital to analog using a digital-to-analog converter.

4. The system of claim 2, wherein the analog transmit signal originates from a digital transmit signal converted from digital to analog using a digital-to-analog converter;

wherein the sampled digital transmit signal is sampled digitally from the digital transmit signal of the communication system prior to digital-to-analog conversion.

5. The system of claim 1, further comprising an analog self-interference canceller;

wherein the analog self-interference canceller generates, using an analog transmit signal of the communication system, an analog self-interference cancellation signal that is combined with the receive signal in analog;

further comprising a digital-to-analog converter that converts the digital self-interference cancellation signal to a digitally-sourced analog self-interference cancellation signal;

wherein the digitally-sourced analog self-interference cancellation signal is combined with the receive signal in analog.

6. The system of claim 5, wherein the digitally-sourced analog self-interference cancellation signal is combined with the receive signal after combination of the analog self-interference cancellation signal with the receive signal.

7. The system of claim 6, wherein the sampled digital transmit signal is sampled from the analog transmit signal using an analog-to-digital converter;

wherein the analog transmit signal originates from a digital transmit signal converted from digital to analog using a digital-to-analog converter.

8. The system of claim 6, wherein the analog transmit signal originates from a digital transmit signal converted from digital to analog using a second digital-to-analog converter;

wherein the sampled digital transmit signal is sampled digitally from the digital transmit signal of the communication system prior to digital-to-analog conversion.

9. The system of claim 5, wherein the digitally-sourced analog self-interference cancellation signal is combined with the receive signal before or coincident with combination of the analog self-interference cancellation signal with the receive signal.

10. The system of claim 9, wherein the sampled digital transmit signal is sampled from the analog transmit signal using an analog-to-digital converter;

wherein the analog transmit signal originates from a digital transmit signal converted from digital to analog using a digital-to-analog converter.

11. The system of claim 9, wherein the analog transmit signal originates from a digital transmit signal converted from digital to analog using a second digital-to-analog converter;

wherein the sampled digital transmit signal is sampled digitally from the digital transmit signal of the communication system prior to digital-to-analog conversion.

12. The system of claim 1, wherein the controller samples the controller-sampled digital residue signal at the digital residue signal either prior to filtering by the filter or after being passed by the filter without filtering;

wherein the controller dynamically sets the digital transform configuration in response to changes in the digital residue signal.

13. The system of claim 12, wherein the filter filters the digital residue signal according to a first set of filtering parameters;

wherein the controller dynamically sets the first set of filtering parameters in response to changes in the digital residue signal.

14. The system of claim 12, wherein the controller samples a second controller-sampled digital residue signal at the first reduced-noise digital residue signal after filtering by the filter;

wherein the filter filters the digital residue signal according to a first set of filtering parameters;

wherein the controller dynamically sets the first set of filtering parameters in response to changes in the first reduced-noise digital residue signal.

15. The system of claim 14, wherein the controller dynamically sets the first set of filtering parameters in response to changes in both of the first reduced-noise digital residue signal and the digital residue signal.

16. The system of claim 12, wherein the filter generates the first reduced-noise digital residue signal from the digital residue signal according to a first set of filtering parameters;

wherein the filter additionally generates a second reduced-noise digital residue signal from the digital residue signal according to a second set of filtering parameters;

wherein the controller samples a second controller-sampled digital residue signal at the second reduced-noise digital residue signal after filtering by the filter;

wherein the controller dynamically sets the first set of filtering parameters in response to changes in the second reduced-noise digital residue signal.

17. The system of claim 16, wherein the controller dynamically sets the first set of filtering parameters in response to changes in both of the second reduced-noise digital residue signal and the digital residue signal.

18. The system of claim 17, wherein the controller further dynamically sets the second set of filtering parameters in response to changes in both of the second reduced-noise digital residue signal and the digital residue signal.

19. The system of claim 1, wherein the controller samples the controller-sampled digital residue signal at the first reduced-noise digital residue signal after filtering by the filter;

wherein the controller dynamically sets the digital transform configuration in response to changes in the first reduced-noise digital residue signal.

20. The system of claim 19, wherein the filter filters the digital residue signal according to a first set of filtering parameters;

wherein the controller dynamically sets the first set of filtering parameters in response to changes in the first reduced-noise digital residue signal.

21. The system of claim 1, wherein the filter generates the first reduced-noise digital residue signal from the digital residue signal according to a first set of filtering parameters;

wherein the filter additionally generates a second reduced-noise digital residue signal from the digital residue signal according to a second set of filtering parameters;

wherein the controller samples the first controller-sampled digital residue signal at the second reduced-noise digital residue signal after filtering by the filter;

wherein the controller dynamically sets the first set of filtering parameters in response to changes in the second reduced-noise digital residue signal.

22. The system of claim 21, wherein the controller dynamically sets the second set of filtering parameters in response to changes in the second reduced-noise digital residue signal.