New super-exponential iteration blind equalization algorithm for underwater acoustic communications

A new super-exponential decision feedback blind equalization algorithm is proposed in this paper. In comparison with the conventional SEI-DFE equalization algorithm, the proposed algorithm presents a new fast convergence weight update error function. Therefore, phase compensation ability and steady-state Mean Square Error (MSE) performance have been increased, but they don´t significantly increase the computational complexity. At the same time, a second order digital phase-locked loop is introduced in order to track and compensate phase rotation. The MSE and carrier recovery performance of the proposed algorithm are better than that of the SEI-DFE algorithm, which is verified by computer simulation. In addition, the MULAN Lake experiment shows that the performance of the proposed algorithm is better than that of the SEI-DFE algorithm in terms of Bit Error Rate (BER) by comparing the influences causing filter weight vector length, step size and Q matrix size.