脉冲编码调制 (PCM)：
它是用于将模拟信号转换为数字信号的技术。 PCM 具有良好或合理的信噪比。对于传输，脉冲编码调制需要高发射机带宽。 PCM技术分为三个要素，首先是提供端的传输，其次是传输路径的再生，以及接收端。
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增量调制(DM)：
Delta 调制是一种模数和数模信号转换技术。采用Delta调制实现高信噪比。它使用一位PCM码来实现模拟信号的数字传输。使用增量调制，不是仅传输一个样本的编码说明，而是仅传输一个比特，这仅指示样本是大于还是小于前一个样本。它是最好或最简单的差分脉冲编码调制类型。 Delta 调制信号比脉冲编码调制系统小。
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如果信号很大，则数字数据中的下一位为 1，否则为 0。脉冲编码调制 (PCM) 和增量调制 (DM) 的区别：
| S.NO | PCM | DM |
|---|---|---|
| 1. | PCM stands for Pulse Code Modulation. | DM stands for Delta Modulation. |
| 2. | In PCM, feedback does not exist in transmitter or receiver. | While in DM, feedback exists in transmitter. |
| 3. | Per sample 4, 8, or 16 bits are used. | Here, only one bit is used per sample. |
| 4. | PCM requires highest transmitter bandwidth. | DM requires lowest transmitter bandwidth. |
| 5. | PCM is complex in terms of complexity of implementation. | While DM is simple in terms of complexity of implementation. |
| 6. | PCM has good signal to noise ratio. | While DM has poor signal to noise ratio. |
| 7. | PCM is costly. | DM is cheap. |
| 8. | PCM may be a technique wont to digitally represent sampled analog signals. | Digital to analog and analog to digital converter. |
| 9. | In PCM, signal requires encoder and decoder both sides. | In DM, signal can modulate and demodulate. |
| 10. | PM is mostly used in video telephony and audio telephony. | DM is mostly used in speeches as well as images. |