Threshold-based sparse channel estimation for Long-Range OFDM underwater acoustic system

This paper presents a convolutional-coded orthogonal frequency division multiplexing (OFDM) system designed for the long-range underwater acoustic channel with its attendant sparse multipath channels and Doppler effects. Based on the carrier frequency offset (CFO) compensation, a threshold-based sparse channel estimation algorithm is proposed by maximizing the probability of distinguishing between taps with significant and small energy. Simulation results demonstrate that the proposed sparse channel estimation is better than existing ones. OFDM receiver performance is further evaluated through simulations.