Systems and methods for near band interference cancellation

• US 9,712,312 B2
• Filed: 03/26/2015
• Issued: 07/18/2017
• Est. Priority Date: 03/26/2014
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Kumu Networks, Inc.
• Inventors: Bharadia, Dinesh, Hong, Steven, Mehlman, Jeffrey, Choi, Jung-Il, Jain, Mayank
• Primary Examiner(s): Marcelo, Melvin
• Assistant Examiner(s): Pascual Peguero, Natali N
• Application Number:
  US14/670,321
• Publication Number:
  US 20150280893A1
• Time in Patent Office: 845 Days
• Field of Search: 370202, 370268, 370281
• CPC Class Codes: H04B 1/525 with means for reducing leakage of transmitter signal into the receiver
• CPC Class Codes: H04L 5/14 Two-way operation using the same type of signal, i.e. duplex

Abstract

A method for self-interference canceller tuning for a near band radio includes receiving, in a first frequency band, an RF transmit signal of the near band radio; receiving, in a second frequency band, an RF receive signal of the near band radio; generating a self-interference cancellation signal from the RF transmit signal based on a set of configuration parameters; combining the self-interference cancellation signal with the RF receive signal to create a composite receive signal; and adapting the set of configuration parameters based on the compo-site receive signal.

Claims

1. A method for self-interference canceller tuning for a near band radio comprising:

receiving, in a first frequency band, an RF transmit signal of the near band radio;

receiving, in a second frequency band, an RF receive signal of the near band radio;

retuning a transmitter of the near band radio from the first frequency band to the second frequency band;

transmitting a weak signal on the second frequency band;

retuning the transmitter of the near band radio from the second frequency band to the first frequency band;

generating knowledge of a receive channel based on the weak signal;

generating a self-interference cancellation signal from the RF transmit signal based on a set of configuration parameters;

wherein generating the self-interference cancellation signal comprises combining a set of filtered, scaled, and delayed versions of the RF transmit signal;

combining the self-interference cancellation signal with the RF receive signal to create a composite receive signal; and

adapting the set of configuration parameters based on the composite receive signal;

wherein adapting the set of configuration parameters based on the composite receive signal comprises adapting scaling factors and delays;

wherein the first frequency band and second frequency band are non-identical.

2. The method of claim 1, wherein adapting the set of configuration parameters comprises adapting a set of complex weights and a set of delays.

3. The method of claim 1, wherein adapting the set of configuration parameters further comprises using a constrained optimization algorithm to adapt configuration parameters based on knowledge of transmit and receive channels of the near band radio.

4. The method of claim 3, further comprising performing transceiver retuning to generate the knowledge of transmit and receive channels.

5. The method of claim 3, wherein the constrained optimization algorithm is an alternating direction method of multipliers algorithm.

6. The method of claim 1, wherein adapting the set of configuration parameters further comprises estimating a self-interference channel from a ratio of receive and transmit channels and adapting the set of configuration parameters based on the estimated self-interference channel.

7. The method of claim 6, wherein estimating a self-interference channel from a ratio of receive and transmit channels comprises:

measuring a first magnitude of the composite receive signal, wherein the first magnitude is measured for a first set of configuration parameters;

measuring a second magnitude of the composite receive signal, wherein the second magnitude is measured for a second set of configuration parameters; and

determining self-interference channel phase and magnitude from a difference of the first magnitude and the second magnitude and from a difference of the first set of configuration parameters and the second set of configuration parameters.

8. The method of claim 7, further comprising detecting that transmit signal noise is a dominant component of the composite receive signal.

9. The method of claim 6, wherein adapting the set of configuration parameters further comprises adapting the set of configuration parameters using a constrained optimization algorithm.

10. The method of claim 1, wherein the weak signal is a noise signal with known characteristics.

11. The method of claim 1, wherein retuning the transmitter comprises changing a local oscillator frequency of the transmitter.

12. The method of claim 1, wherein retuning the transmitter comprises changing a signal path of the transmitter.