Efficient Symbol Detection via Beamforming Preprocessing for OTFS Underwater Acoustic Communications

Orthogonal time frequency space (OTFS) modulation has attracted considerable attention in underwater acoustic (UWA) communications due to its inherent advantages under time-varying channels. In this paper, we propose an efficient symbol detection scheme via beamforming preprocessing for OTFS UWA systems employing a receive array. The beamforming is performed in the time-frequency domain, and it brings array gain as well as complexity reduction. The beamformed signal was transformed to the delay-Doppler domain, where a direct adaptive equalizer (DAE) is adopted to recover transmitted symbols. Simulation and experimental results verified the advantages of the proposed beamforming-based multichannel DAE (BF-DAE) over existing solutions.