脉冲编码调制（PCM）是数字通信的编码方式之一，在通信系统中完成将语音信号数字化的功能。PCM的实现主要包括三个步骤：抽样、量化、编码，分别完成时间上离散、幅度上离散及量化信号的二进制表示。-Pulse code modulation (PCM) is one of the encoding of digital communications, in a communication system will complete the function of digital speech signals. The realization of the PCM mainly includes three steps: sampling, quantization and coding, completed on the discrete time, the amplitude of discrete and quantify the binary representation of signals.