一、引言模拟信号经过抽样和幅度量化变成时间上和幅度上都是离散的信号,这样可以用一组二进制数字去代表每一个量化后的样值了,这一变换过程称为编码。在具体的电路实现中往往都是将量化和编码这二个过程同时进行的,即将PAM信号与量化判定值进行比较、确定出信号所处的量化层时,编码器也就同时编出与该量化层相当的二进制数码信号,这样就最后完成了模拟信号到数字信号的变换,通常把编码器称为模/数变换器(A/D)。将二进制 I. INTRODUCTION After analog signals are sampled and amplitude quantized, they become discrete signals both in time and in amplitude, so that each group of quantized samples can be represented by a set of binary numbers. This transformation is called coding. In specific circuit implementations are often both quantization and encoding process at the same time, the PAM signal is compared with the quantization decision value to determine the signal where the quantization layer, the encoder will also be compiled simultaneously with the Quantization layer equivalent binary digital signal, so that the final completion of the analog signal to digital signal conversion, the encoder is usually referred to as A / D converter. Will be binary