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PCM 意为脉冲编码调制,简称脉码调制,是将模拟信号转换成为一系列相应的脉冲信号的一种编码方式,它分为采样、量化、编码三个过程。首先按一定的时间间隔取出模拟信号的瞬时值,产生脉冲调幅信号(PAM),这个过程称为采样,为了在解码时能够不失真地恢复出原始模拟信号,采样频率应大于模拟信号最高频率的两倍。例如,要保证16kHz 的音频带宽,采样频率至少要达到32kHz。采样后,用标准幅度量出每一个脉冲幅度大小,按四舍五入的原则使采样值整数化,这一过程称为量
PCM means pulse code modulation, referred to as pulse code modulation, is the analog signal into a series of corresponding pulse signal encoding, it is divided into sampling, quantization, encoding three processes. Firstly, the instantaneous value of the analog signal is taken out at a certain time interval to generate a pulsed amplitude modulation signal (PAM). This process is called sampling. In order to recover the original analog signal without distortion when decoding, the sampling frequency should be greater than the highest frequency of the analog signal double. For example, to ensure 16kHz audio bandwidth, the sampling frequency should be at least 32kHz. After sampling, measure the magnitude of each pulse with the standard amplitude, and round off the sampling value according to the principle of rounding. This process is called quantity