说明：  1、用Matlab绘制带通信号图形 2、用Matlab对模拟信源进行均匀量化 3、用Matlab编制一个函数实现均匀PCM量化编码，并计算量化噪声比(SQNR) 4、用Matlab对不同的量化级数计算出相应的量化噪声比
(1, drawn using Matlab graphics bandpass 2, the simulation using Matlab source for uniform quantization 3, prepared using Matlab function to achieve a uniform PCM quantization coding, and calculate the quantization noise ratio (SQNR) 4, using Matlab on a different series to calculate the corresponding quantitative quantization noise ratio)