Filter design for self-interference cancellation

Mitigation of self-interference is the prime challenge in making full-duplex technology feasible in wireless communications. In this chapter, we first present system model of a wireless communication link including a source, full-duplex transceiver, and destination, and discuss different approaches and assumptions when building the signal model. Then we will present frequency, time, and spatial signal processing techniques to mitigate self-interference in digital baseband. We concentrate on time-domain filtering instead of frequency-domain filtering on a subcarrier basis, because time-domain filtering need not assume OFDM waveforms or synchronization between transmitted and received signals. We complement the time-domain filtering with spatial filters that together are able to mitigate the effects of non-linear transmitter distortions using only linear operations.