Using a New Channel Estimation Algorithm to Improve Underwater Acoustic Communication with Multiple Receivers

Underwater acoustic (UWA) communication with multiple receivers has been developed for underwater wireless data transmission, because the receiving array can improve the reliability of the system by using spatial diversity. In this paper, a channel estimation algorithm is proposed that fully uses UWA channel sparsity for single-input, multiple-output (SIMO) communication. The proposed algorithm integrates L-0 norm into the cost function of the improved proportionate normalized least-mean-square (IPNLMS) algorithm based on L-0 norm. The performance of the L-0 norm- constrained IPNLMS, IPNLMS based on L-0 norm, and the proposed algorithm is studied in terms of normalized misalignment for SIMO UWA channel estimation. In addition, the influence of the number of receivers on channel estimation accuracy is analyzed. Finally, the numerical simulation results demonstrate the superiority of the proposed algorithm in terms of robustness, which achieves the lower normalized misalignment than the other two algorithms in a shallow-water acoustic channel estimation.