Performance of Micro-Modem PSK signaling under variable conditions during the 2008 RACE and SPACE experiments

During the ONR-funded acoustic communications experiments conducted in Rhode Island and Massachusetts in 2008 more than ten investigators participated with new signals and receivers with the intent of establishing performance for next-generation acoustic communications systems. 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. These signals serve as a benchmark for the current generation of multi-channel algorithms that use a decision-feedback equalizer with least-mean squares adaptation which can run in real-time on a low-power DSP. Performance was tested using a QPSK signal with 5 kHz bandwidth and error-correction coding that results in approximately 5000 bps burst throughput in the actual modem.