UAMP-SBL Based Channel Estimation for Underwater Acoustic Communications with Receiver Array

Compared with wireless channels, underwater acoustic (UWA) channels are much more challenging. To achieve satisfactory performance, a receiver array is commonly employed to achieve diversity gain or array gain. In UWA communications, people has focused on diversity gain of the receiver array and the array gain is generally overlooked. With the advent of massive MIMO technique, some recent efforts have been made to make use of array gain in UWA communications. In this case, angle information needs to be explicitly incorporated into the UWA channel model. In this paper, we propose a channel estimation scheme based on the combination of UAMP and SBL algorithms, achieving a tradeoff of performance and complexity. In the proposed scheme, angle, delay, and amplitude of the UWA channel are all estimated. Simulation and experimental results both verified the UAMP-SBL channel estimation scheme outperforms traditional channel estimation methods.