说明：  考虑一个线性自适应均衡器的原理方框图如《现代数字信号处理导论》p.275自适应均衡器应用示意图。用LMS算法实现这个自适应均衡器，画出一次实验的误差平方的收敛曲线，给出最后设计滤波器系数。一次实验的训练序列长度为500。进行20次独立实验，画出误差平方的收敛曲线。给出3个步长值的比较。
(consider a linear adaptive equalizer block diagram as the principle of "modern digital signal processing" Introduction to the p.275 adaptive equalizer application schema. LMS algorithm with the adaptive equalizer, painted a square experimental error of convergence curve, given final design filter coefficients. Experimental a length of the training sequence to 500. Conduct 20 separate experiments, painted square error of the convergence curve. Given three step-value comparisons.)