Systems and methods for near band interference cancellation

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.