Comparisons of Channel Estimation for OFDM-based and Wavelet-based Underwater Acoustic Communications

In this paper, a wavelet-based underwater acoustic (UWA) communication system is proposed. The convolutional structure of the UWA channel is exploited and the pilot assisted channel estimation is formulated as a sparse recovery problem. Then the restricted isometry property (RIP) of the measurement matrix is investigated via eigenvalue analysis and Gersgorin circle theorem. It's proved that the sparse recovery of the wavelet-based UWA channel satisfies the RIP. With the above setup, comparisons of channel estimation for OFDM-based and wavelet-based UWA communication systems are deployed. Simulation results show that the wavelet-based system achieves more accurate channel estimation performance than the OFDM-based system under the same conditions of bandwidth, duration, data rate and channel profile.