Multipath Self-interference Cancellation Based on Segment Inverse Transform Method for Wireless Full-Duplex Systems

For cancelling the multipath self-interference (SI) signals in wireless full-duplex communications, multi-tap cancellation circuit in the analog-domain requires large amounts of taps and complex tuning algorithm. In this paper, a digitally assisted analog cancellation scheme is proposed, which utilizes segment inverse transform method (SITM) to generate digital cancelling parameters based on Rayleigh fading model, and converts the cancellation signal to analog-domain through an auxiliary transmit chain. Comparing to other digitally assisted analog cancellation schemes, the proposed scheme is able to simplify the cancellation circuit, since it is free of building complex channel model in the digital domain. Simulation results show that when the number of propagation paths is 20, the amount of cancellation is 5 dB higher than the current scheme in literature, and it is less affected by the number of paths.