Improved multipath robustness of DFH modulation in the underwater acoustic channel

We characterize performance improvement of differential frequency hopping modulation under two techniques that mitigate the multipath effects of the underwater acoustic channel: blind adaptive equalization and beamforming. We report results on data collected at-sea during the RACE08, SPACE08 and WHOI09 experiments, and show that the bit-error rate improves with the application of these two techniques. Future improvements may combine joint single-element, blind equalization and beamforming (multi-element) approaches to leverage their respective strengths.