Patent ID: 9698836
Date: 2017-07-04
CPC Classifications: H03F,H04B,H04L

Claim:
1. A multi-stage self-interference cancellation system, the system comprising: a transmit signal sampling module coupled to a transmit signal path of a communication station and configured to sample a transmit signal after modification of the transmit signal by a nonlinear component of the transmit signal path, wherein the communication station is operable to transmit and receive using a same frequency simultaneously; a receive signal sampling module coupled to a receive signal path of the communication station and configured to sample a radio frequency (RF) receive signal as received by the communication station including self-interference from the simultaneous transmitting and receiving using the same frequency; a channel estimation module coupled to the transmit signal sampling module and the receive signal sampling module and configured to receive a transmit sample signal from the transmit signal sampling module and a receive sample signal from the receive signal sampling module, wherein the transmit sample signal and the receive sample signal undergo analog to digital conversion prior to reception by the channel estimation module, the channel estimation module further configure to determine a baseband channel estimate from the received transmit sample signal and the receive sample signal, and to perform digital to analog conversion of the baseband channel estimate to generate RF channel parameters; an analog cancellation module coupled to the receive signal path and configured to provide an RF cancellation signal thereto, wherein combining the RF receive signal and the RF cancellation signal provides cancellation of strong self-interference resulting in a residual signal, and wherein the analog cancellation module comprises a multi-tap vector modulation module configured to generate the RF cancellation signal, wherein the RF channel parameters adaptively control the multi-tap vector modulation module to generate the RF cancellation signal to reduce interference in signals received over a time-varying multipath channel; and a digital cancellation module coupled to the receive signal path and configured to provide a residual cancellation signal thereto, wherein combining the residual signal and the residual cancellation signal provides a desired receive signal having the self-interference mitigated.