An Adaptive Receiver for Underwater Acoustic Full-Duplex Communication with Joint Tracking of the Remote and Self-Interference Channels

TL;DR

This paper introduces an adaptive receiver for underwater acoustic full-duplex communication that jointly tracks self-interference and remote channels using recursive least squares, enhancing SI cancellation and bandwidth efficiency in dynamic environments.

Contribution

It presents a novel joint channel tracking method using RLS algorithms that improves self-interference cancellation without frequent training sequences.

Findings

Enhanced SI cancellation compared to separate estimators

Real-time channel tracking preserves bandwidth efficiency

Effective in rapidly changing underwater environments

Abstract

Full-duplex (FD) communication is a promising candidate to address the data rate limitations in underwater acoustic (UWA) channels. Because of transmission at the same time and on the same frequency band, the signal from the local transmitter creates self-interference (SI) that contaminates the signal from the remote transmitter. At the local receiver, channel state information for both the SI and remote channels is required to remove the SI and equalize the SI-free signal, respectively. However, because of the rapid time-variations of the UWA environment, real-time tracking of the channels is necessary. In this paper, we propose a receiver for UWA-FD communication in which the variations of the SI and remote channels are jointly tracked by using a recursive least squares (RLS) algorithm fed by feedback from the previously detected data symbols. Because of the joint channel estimation, SI cancellation is more successful compared to UWA-FD receivers with separate channel estimators. In addition, due to providing a real-time channel tracking without the need for frequent training sequences, the bandwidth efficiency is preserved in the proposed receiver.