Wideband self-interference cancellation for better spectrum use

Abstract

A large enough separation in the frequency domain between signals going in opposite directions is instrumental to facilitate the implementation of transceivers able to isolate the receiver from the high power transmitted signal. A more flexible allocation of spectrum requires the application of interference cancellation countermeasures. In this paper we address the digital processing involved in the realization of echo cancelling filters in the analog domain, designed to avoid the saturation of the receiver front-end due to the coupling of the transmitted signal and its out-of-band content. The design goal will be the reduction of the sampling rates, so large bandwidth interference waveforms can be attenuated working at sub-Nyquist rates.