A Low-Complexity Orthogonal Matching Pursuit Based Channel Estimation Approach for Underwater Acoustic Baseband OFDM System

In this paper, we propose a low-complexity Orthogonal Matching Pursuit (OMP) based channel estimation approach for underwater acoustic (UWA) baseband orthogonal frequency division multiplexing (OFDM) system, where the doubly-spread characteristic of channels is taken into account. In the proposed method, an adaptive inertia weight particle swarm optimization (AwPSO) algorithm is developed to optimize the search procedure. Subsequently, the newly proposed method, namely AwPSO-OMP, avoids calculating all Hermitian inner products of the candidates at each iteration and achieves a low computational complexity. Simulation results and experimental validation both demonstrate the effectiveness of the proposed method in UWA doubly-spread channels. Compared with the standard OMP method, the proposed method achieves the remarkable benefit in the computational complexity with the equivalent bit error rates (BERs).