水声信道中严重的多普勒频移效应和大量的脉冲噪声会对判决反馈均衡算法的稳健性和抗多径性能造成恶劣影响,从提高判决反馈盲均衡算法稳健性的角度出发,采用前、反均衡滤波器系数变化量的Euclid范数作为代价函数,提出了一种新型判决反馈盲均衡算法,并针对算法存在的问题,引入判决导引、锁相、判决正方形机制进行了改进。仿真结果表明,在高阶QAM通信系统中,新的判决反馈盲均衡算法在保持判决反馈机制优势的同时,大大提高了算法的稳健性,同时表现出收敛能力强、收敛速度快等综合性能。
Doppler frequency shift and a lot of impulse noises existing in the underwater acoustic channels will deteriorate the robustness and anti multipath effects of the decision feedback equalization algorithm. Aiming to improve the robustness of decision feedback equalization algorithm,this article brings forward one new equalization algorithm which takes Euclid norm of changes in both forward and feedback equalization filters as the cost function. Also,the algorithm includes DD、PLL and square decision technique to achieve better performances. The results of simulation show that this new decision feedback equalization algorithm performs stronger robustness as well as great convergence ability and fast convergence speed and maintains the advantages of traditional decision feedback equalizer.