增量调制 (DM) 和差分脉冲编码调制 (DPCM) 之间的区别

增量调制 (DM)：
Delta 调制是关联模拟到数字和数字到模拟信号转换技术。 Delta 调制用于欣赏高信噪比幅度关系。它使用一位PCM码来欣赏模拟信号的数字传输。使用增量调制，而不是传输样本的编码说明，仅传输一位，这仅指示样本是否大于或小于前一个样本。它是最有效或最简单的差分脉冲编码调制。 Delta 调制信号比脉冲编码调制系统小。

差分脉冲编码调制 (DPCM)：
DPCM 代表差分脉冲编码调制，与用于将模拟信号转换为数字信号的脉冲编码调制技术相同。差分脉冲编码调制具有中等的信噪幅度关系。差分脉冲编码调制不同于脉冲编码调制，因为它量化了实际样本和预期值的优劣。这就是它被称为差分脉冲编码调制(DPCM)的原因。
DPCM 发送器和 DPCM 接收器操作如下图所示：

在上图中，如果信号很大，则数字数据中的下一位为 1，否则下一位为 0。

让我们看看DM和DPCM之间的区别，下面给出：

S.NO	Comparison based on	DM	DPCM
1.	Feedback	In DM, feedback exists in transmitter.	Here, feedback exists in both transmitter and receiver.
2.	signal to noise ratio	DM has poor signal to noise ratio.	DPCM has fair signal to noise ratio.
3.	Transmission bandwidth	It requires lowest bandwidth.	Here, DPCM requires less bandwidth than PCM.
4.	Levels, step size	In DM, step size is fixed.	While here, number of levels are fixed.
5.	Efficiency	DM is less efficient than DPCM.	DPCM is more efficient.
6.	Number of bits	In DM, only one bit is used per sample.	Here more than one but less than PCM(Pulse Code Modulation) bits are used.
7.	Quantization error and distortion	Slop overload distortion and granular noise are present.	Slop overload distortion and quantization noise are present.
8.	Applications	It is generally used in speeches and images.	It is mostly used in videos and speeches.