Performance of Micro-Modem PSK signaling with a mobile transmitter during the 2010 MACE experiment

During the 2010 MIMO Acoustic Communications Experiment (MACE) sponsored by ONR, 12 investigators participated with new signals and receiver algorithms with the goal of establishing performance for next-generation acoustic communications systems using a towed transmitter. In addition to testing these new approaches, the signals developed and used for the WHOI Micro-Modem over the past ten years were also transmitted and collected on several different receivers. These signals serve as a benchmark for the current generation of multichannel algorithms that use a decision-feedback equalizer with least-mean squares adaptation that can run in real-time on a low-power DSP. Performance was tested using a QPSK signal with 5 kHz bandwidth and two types of error-correction coding that result in approximately 520 bps burst throughput for the low rate packet and 5000 bps burst throughput for the high rate packet in the actual modem, using a carrier of 13 kHz. The test provided an excellent performance benchmark and complements previous work done during the ONR-funded RACE and SPACE experiments. The deeper-water propagation channel and the mobility of the transmitter during MACE provided for additional performance data in a more highly time-varying environment.