运用MATLAB语言，进行非均匀PCM量化编码。产生一个长度为500，按N（0，1）分布的随机变量序列。用64量化电平和μ=255的μ律非线性，画出量化器的误差和输入输出关系。-Using MATLAB language, non-uniform quantization PCM coding. Produces a length of 500, according to the sequence of random variables N (0,1) distribution. With 64 quantization levels μ = μ-law nonlinearity 255, draw error and input-output relationship quantizer.