Reliable Acoustic Link using Non-coherent Turbo-coded Frequency Shift Keying

Low-data rate, non-coherent algorithms were tested at 10 km distances to measure reliability and robustness when combined with convolutional turbo encoding techniques. The system was constrained to hardware specifications limiting bandwidth at low frequencies. Simulations were used to verify the performance of varying algorithms in Bellhop modeled channel impulse responses. The algorithms were tested at sea to compare simulation capabilities with real environmental characteristics. The objectives: (1) define a modulation scheme for robust communication in underwater environments, (2) simulate its performance in multipath and Doppler rich environments, and (3) test performance of modulation scheme in actual ocean environment.