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

A system for adaptively-tuned digital self-interference cancellation comprising:

• a transmit coupler, communicatively coupled to an analog transmit signal of a transmitter of a communications system, that samples the analog transmit signal to create a sampled analog transmit signal;
• an analog self-interference canceller that generates an analog self-interference cancellation signal from the sampled analog transmit signal;
• a receive coupler, communicatively coupled to an analog receive signal of a receiver of the communications system, that combines the analog self-interference cancellation signal with the analog receive signal, therefore reducing self-interference in the analog receive signal;
• and
• a digital self-interference canceller that generates a digital self-interference cancellation signal from a digital transmit signal of the communications system, the digital self-interference canceller comprising:
• a component generation system that generates a first set of self-interference cancellation signal components from the digital transmit signal;
• a first multi-rate filter that, according to a transform configuration, combines the first set of self-interference cancellation signal components to generate the digital self-interference cancellation signal;
• and
• a transform adaptor that updates the transform configuration;
• wherein the digital self-interference cancellation signal is combined with a digital receive signal to form a digital residue signal;
• wherein the digital self-interference canceller generates a composite residue signal, non-identical to the digital residue signal, from the digital residue signal and the digital transmit signal;
• wherein the transform adaptor updates the transform configuration based on the composite residue signal.