Optimal Bayesian Resampling for OFDM Signaling Over Multi-scale Multi-lag Channels

Underwater acoustic (UWA) communication channels are ultra-wideband in nature and experience long delay spreads and significant Doppler effects. The typical UWA channel distortion can be described by a multi-scale, multi-lag (MSML) channel model. Many UWA communication systems employ resampling by a single-scale at the front-end to compensate for the scale effects of UWA channels. In this letter, the optimal resampling parameter for OFDM signaling over MSML channels is investigated from a Bayesian perspective. The resampling parameter is selected to minimize the inter-carrier interference (ICI) resulting from the MSML channel for OFDM signaling. The exact interference energy is computed, but is intractable for optimization, thus, an upper bound is employed for optimization. Numerical results verify the tightness of the bound and quantify the performance of the Bayesian approach. As expected, the proposed method outperforms previous deterministic methods for resampling in MSML channels, which in turn outperform the classical packet-length-based approach, and is more effective in ICI mitigation.