Joint Equalization and Self-Interference Cancellation for Underwater Acoustic In-Band Full-Duplex Communication

In-band full-duplex (IBFD) communication in underwater acoustic channels is challenged by strong and time-varying self-interference (SI). To detect data symbols, the receiver needs to suppress the SI and equalize the resultant signal to compensate for the intersymbol interference (ISI) caused by the remote transmission (RT) channel. In this article, we develop a new receiver that combines adaptive decision feedback equalizer and SI cancellation (ADFE-SIC) to jointly eliminate the ISI and SI. A recursive least squares algorithm adaptively estimates the filters in ADFE-SIC. By conducting simulations and experimental tests, we show that the proposed method outperforms the conventional approach in which equalization and SI cancellation tasks are performed separately and the filter configuration is based on prior estimations of the SI and the RT channels.