Experimental Evaluation of OTFS for Underwater Acoustic Communications

This paper applies the Orthogonal Time-Frequency Space (OTFS) modulation to underwater mobile acoustic communications where the communication channel suffers from severe multipath and Doppler effects simultaneously. Field experiments have been conducted with acoustic transmission at a center frequency of 115 kHz and a data rate of 11.5 kilosymbols per second. We propose a new Turbo Decision Feedback Equalizer and Decoder (TDFED) for the receiver and the experimental results demonstrate the superior performance of the proposed TDFED algorithm over existing MMSE equalizers.