基于判决导引的水声信道混合盲均衡算法研究

On hybrid blind equalization algorithm based on decision-directed for underwater acoustic channel

提出了一种适用于正交幅度调制(QAM)信号的混合盲均衡算法,该算法在初始模式中分别对QAM信号的同相分量和正交分量进行均衡,利用方形环判决域对均衡器输出信号进行判决,当误码率降到足够低的水平时自动切换到判决导引最小均方误差算法。最后利用水声信道仿真模型,对该算法的性能进行了验证。结果表明:该算法性能稳健,收敛后均方误差小,有效降低了高速水声通信的误码率,提高了水声信道均衡的稳定性,且有良好的冷启动和重新启动能力。

A hybrid algorithm suitable for high-order QAM signals is presented. Equalization of the in-phase and quadrature components of constellation symbols is implemented respectively at the first mode. Equalizer＇s outputs are decided by square ring decision region. The proposed algorithm switches over to Decision-Directed equalization scheme smoothly once the error level is reasonably low. Simulation tests are conducted using underwater acoustic channel model. The results prove that the proposed algorithm has the advantages of robustness, low residual mean square error, cold start and restart ability, and can greatly reduce the error rate and improve the robustness of high-speed underwater acoustic communication.