Method for pilot signal based self-inteference cancellation tuning

• US 9,673,854 B2
• Filed: 01/29/2016
• Issued: 06/06/2017
• Est. Priority Date: 01/29/2015
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Kumu Networks, Inc.
• Inventors: Choi, Jung-Il, Mehlman, Jeff, Jain, Mayank
• Primary Examiner(s): Vuong, Quochien B
• Application Number:
  US15/011,093
• Publication Number:
  US 20160226535A1
• Time in Patent Office: 494 Days
• Field of Search: 455 631, 4551151, 4551152, 455295, 455296, 455423, 455425, 370277, 370278, 370282, 370286, 370292, 375346
• CPC Class Codes: H04B 1/525 with means for reducing leakage of transmitter signal into the receiver

Abstract

A method for pilot signal based self-interference cancellation tuning includes detecting a tuning trigger and in response to the tuning trigger, generating a pilot transmit signal according to the trigger data; and transmitting, at the transmitter, the pilot transmit signal; receiving, at the receiver, a pilot receive signal; cancelling, at the self-interference canceller, a portion of self-interference in the receive pilot signal, resulting in a composite pilot signal; analyzing the composite pilot signal; and tuning a configuration parameter of the self-interference canceller, based on analysis of the composite pilot signal, resulting in reduced self-interference in the composite pilot signal.

Claims

1. A method for pilot signal based self-interference cancellation tuning comprising:

transmitting, at a transmitter of a communication system, a transmit signal;

receiving, at a receiver of the communication system, a receive signal;

cancelling, at a self-interference canceller of the communication system, a portion of self-interference in the receive signal, resulting in a composite receive signal;

analyzing the composite receive signal;

generating a tuning trigger in response to analysis of the composite receive signal;

detecting the tuning trigger;

in response to the tuning trigger;

pausing transmission of the transmit signal; and

transmitting, at the transmitter, a pilot transmit signal;

receiving, at the receiver, a pilot receive signal;

cancelling, at the self-interference canceller, a portion of self-interference in the pilot receive signal, resulting in a composite pilot signal;

analyzing the composite pilot signal;

tuning a configuration parameter of the self-interference canceller, based on analysis of the composite pilot signal, resulting in reduced self-interference in the composite pilot signal; and

pausing transmission of the pilot transmit signal and resuming transmission of the transmit signal.

2. The method of claim 1, wherein analyzing the composite receive signal comprises measuring the signal strength of the composite receive signal.

3. The method of claim 2, further comprising generating the tuning trigger in response to the signal strength of the composite receive signal exceeding a predetermined threshold.

4. The method of claim 1, wherein the self-interference canceller comprises an analog self-interference canceller.

5. The method of claim 4, wherein the analog self-interference canceller comprises a filter, a scaler, and a delayer, and tuning the configuration parameter comprises adjusting at least one of a scale factor of the scaler and a delay of the delayer.

6. The method of claim 1, wherein the self-interference canceller comprises a digital self-interference canceller, the digital self-interference canceller comprising a transform function, and tuning the configuration parameter comprises adjusting a weight coefficient of the transform function.

7. The method of claim 1, wherein the self-interference canceller comprises an analog self-interference canceller and a digital self-interference canceller, and further comprising:

tuning a configuration parameter of the analog self-interference canceller, based on analysis of the composite pilot signal, resulting in removal of a first portion of self-interference from the composite pilot signal by the analog self-interference canceller; and

after tuning the configuration parameter of the analog self-interference canceller, tuning a configuration parameter of the digital self-interference canceller, resulting in removal of a second portion of self-interference from the composite pilot signal by the digital self-interference canceller.

8. The method of claim 1, wherein pausing transmission of the pilot transmit signal and resuming transmission of the transmit signal comprises pausing transmission of the pilot transmit signal and resuming transmission of the transmit signal in response to the signal strength of the composite pilot signal power decreasing below a predetermined threshold.

9. The method of claim 1, wherein the transmit signal is transmitted in a first frequency band, the pilot signal is transmitted in a second frequency band, and the first frequency band and the second frequency band are identical.

10. The method of claim 1, wherein the pilot signal is a chirp.

11. The method of claim 1, further comprising analyzing the composite receive signal, and tuning a configuration parameter of the self-interference canceller based on analysis of the composite receive signal.

12. The method of claim 1, wherein tuning the configuration parameter comprises tuning the configuration parameter based on an adaptive online gradient-descent optimization algorithm.

13. A method for pilot signal based self-interference cancellation tuning comprising:

transmitting, at a transmitter of a communication system, a transmit signal;

receiving, at a receiver of the communication system, a receive signal;

detecting a tuning trigger;

wherein the tuning trigger is associated with characteristic trigger data;

wherein the characteristic trigger data comprises an analysis of the receive signal;

in response to the tuning trigger,

generating a pilot transmit signal according to the trigger data;

wherein the pilot transmit signal is generated according to the analysis of the receive signal;

transmitting, at the transmitter, the pilot transmit signal;

receiving, at the receiver, a pilot receive signal;

cancelling, at the self-interference canceller, a portion of self-interference in the receive pilot signal, resulting in a composite pilot signal;

analyzing the composite pilot signal; and

tuning a configuration parameter of the self-interference canceller, based on analysis of the composite pilot signal, resulting in reduced self-interference in the composite pilot signal.

14. The method of claim 13, wherein generating the pilot transmit signal comprises generating the pilot transmit signal using an algorithm;

wherein the algorithm receives the trigger data as an input and outputs the pilot transmit signal.

15. The method of claim 14, wherein using the algorithm comprises selecting the pilot transmit signal from a set of pilot transmit signals, based on the trigger data.

16. The method of claim 15, wherein the set of pilot transmit signals comprises a chirp, an unmodulated sine wave, a superposition of sine waves, and white noise.