脉冲编码调制是数字通信的编码方式之一。主要过程是将话音、图像等模拟信号每隔一定时间进行取样，使其离散化，同时将抽样值按分层单位四舍五入取整量化，同时将抽样值按一组二进制码来表示抽样脉冲的幅值。(PCM pulse code modulation is one of the encoding methods of digital communication. The main process is to voice, image and other analog signal at a certain time for sampling, the discretization, while the sampling values by the hierarchical units four to five homes in rounding quantization, while the sampling value indicates the sample pulse amplitude according to a set of binary code.)