Abstract: A self-interference signal cancellation circuit includes a transmitter for transmitting a transmit signal, a plurality of signal paths, a controller, and a receiver for receiving a signal. Each signal path includes a delay element and a variable attenuator having attenuation levels set by the controller. A combiner generates an output signal by combining outputs of the signal paths. The circuit computes a matrix based on first and second output signals associated with first and second attenuation levels. The controller concurrently varies the attenuation level of each signal path so that a product of the matrix and the attenuation levels of the signal paths is substantially equal to the received signal. The circuit may iteratively compute the matrix using different transmit signal frequencies or with an FFT. The controller iteratively varies the attenuation level of the attenuators until a sum of the product and the received signal satisfies a predefined condition.

Abstract: A system for delay-matched analog self-interference cancellation including a transmit coupler, that samples the analog transmit signal to create a sampled analog transmit signal; a delay matcher that imposes a variable delay on the sampled analog transmit signal to create a delayed analog transmit signal; an analog self-interference canceller that transforms the delayed analog transmit signal to an analog self-interference cancellation signal; and a receive coupler, that combines the analog self-interference cancellation signal with the analog receive signal.

Abstract: A circuit that cancels a self-interference signal includes, in part, a pair of signal paths that are substantially in phase, each of which paths includes a passive coupler, a delay element and a variable attenuator. The circuit further includes, in part, a first group of P signal paths each of which is substantially in phase with the pair of paths, a second group of M signal paths each of which is substantially out-of-phase relative to the pair of signal paths, and at least a pair of feedback paths. Each of the P and M signal paths, as well as the feedback paths includes a delay element and a variable attenuator. Optionally, each of the M signal paths is optionally 180° out-of-phase relative to the pair of signal paths.

Abstract: A system for multi-rate digital self-interference cancellation including a signal component generation system coupled to a digital transmit signal of a communication system that generates a set of signal components from the digital transmit signal; a multi-rate adaptive filter that transforms the set of signal components into a digital self-interference cancellation signal, according to a transform configuration, to form an interference-reduced receive signal; and a transform adaptor that dynamically sets the transform configuration in response to changes in the interference-reduced receive signal.

Abstract: A system and method for analog self-interference cancellation that includes receiving an RF transmit signal of a full-duplex radio; frequency downconverting the RF transmit signal to an IF transmit signal; transforming the IF transmit signal into an IF self-interference signal using an IF analog self-interference cancelling circuit; frequency upconverting the IF self-interference signal to an RF self-interference signal; and combining the RF self-interference signal with an RF receive signal of the full-duplex radio.

Abstract: A system for hybrid self-interference cancellation includes a transmit coupler that samples an RF transmit signal, a RF self-interference canceller that transforms the sampled RF transmit signal to an RF self-interference cancellation signal, an IF self-interference canceller that transforms a downconverted version of the RF transmit signal to an ISRF self-interference cancellation signal, and a receive coupler that combines the RF and ISRF self-interference cancellation signals with an RF receive signal.

Abstract: A system for multi-rate digital self-interference cancellation including a signal component generation system coupled to a digital transmit signal of a communication system that generates a set of signal components from the digital transmit signal; a multi-rate adaptive filter that transforms the set of signal components into a digital self-interference cancellation signal, according to a transform configuration, to form an interference-reduced receive signal; and a transform adaptor that dynamically sets the transform configuration in response to changes in the interference-reduced receive signal.

Abstract: A system for hybrid self-interference cancellation includes a transmit coupler that samples an RF transmit signal, a RF self-interference canceller that transforms the sampled RF transmit signal to an RF self-interference cancellation signal, an IF self-interference canceller that transforms a downconverted version of the RF transmit signal to an ISRF self-interference cancellation signal, and a receive coupler that combines the RF and ISRF self-interference cancellation signals with an RF receive signal.

Abstract: A system for phase noise mitigated communication including a primary transmitter that converts a digital transmit signal to an analog transmit signal, a primary receiver that receives an analog receive signal and converts the analog receive signal to a digital receive signal, an analog self-interference canceller that samples the analog transmit signal, generates an analog self-interference cancellation signal based on the analog transmit signal, and combines the analog self-interference cancellation signal with the analog receive signal and a digital self-interference canceller that samples the digital transmit signal, generates a digital self-interference cancellation signal based on the digital transmit signal, and combines the digital self-interference cancellation signal with the digital receive signal.

Abstract: A system and method for analog self-interference cancellation that includes receiving an RF transmit signal of a full-duplex radio; frequency downconverting the RF transmit signal to an IF transmit signal; transforming the IF transmit signal into an IF self-interference signal using an IF analog self-interference cancelling circuit; frequency upconverting the IF self-interference signal to an RF self-interference signal; and combining the RF self-interference signal with an RF receive signal of the full-duplex radio.

Abstract: A system and method for non-linear digital self-interference cancellation including a pre-processor that generates a first pre-processed digital transmit signal from a digital transmit signal of a full-duplex radio, a non-linear transformer that transforms the first pre-processed digital transmit signal into a non-linear self-interference signal according to a transform configuration, a transform adaptor that sets the transform configuration of the non-linear transformer, and a post-processor that combines the non-linear self-interference signal with a digital receive signal of the full-duplex radio.

Abstract: A circuit that cancels a self-interference signal includes, in part, a pair of signal paths that are substantially in phase, each of which paths includes a passive coupler, a delay element and a variable attenuator. The circuit further includes, in part, a first group of P signal paths each of which is substantially in phase with the pair of paths, a second group of M signal paths each of which is substantially out-of-phase relative to the pair of signal paths, and at least a pair of feedback paths. Each of the P and M signal paths, as well as the feedback paths includes a delay element and a variable attenuator. Optionally, each of the M signal paths is optionally 180° out-of-phase relative to the pair of signal paths.

Abstract: A self-interference signal cancellation circuit includes a transmitter for transmitting a transmit signal, a plurality of signal paths, a controller, and a receiver for receiving a signal. Each signal path includes a delay element and a variable attenuator having attenuation levels set by the controller. A combiner generates an output signal by combining outputs of the signal paths. The circuit computes a matrix based on first and second output signals associated with first and second attenuation levels. The controller concurrently varies the attenuation level of each signal path so that a product of the matrix and the attenuation levels of the signal paths is substantially equal to the received signal. The circuit may iteratively compute the matrix using different transmit signal frequencies or with an FFT. The controller iteratively varies the attenuation level of the attenuators until a sum of the product and the received signal satisfies a predefined condition.

Abstract: A circuit that cancels a self-interference signal includes, in part, a pair of signal paths that are substantially in phase, each of which paths includes a passive coupler, a delay element and a variable attenuator. The circuit further includes, in part, a first group of P signal paths each of which is substantially in phase with the pair of paths, and a second group of M signal paths each of which is substantially out-of-phase relative to the pair of signal paths. Each of the P and M signal paths includes a delay element and a variable attenuator. Furthermore, (P?1) signal paths of the first group of P signal paths, and (M?1) signal paths of the second group of M signal paths include a passive coupler. Optionally, each of the M signal paths is optionally 180° out-of-phase relative to the pair of signal paths.