脉冲编码调制 (PCM):
PCM 是一种用于将模拟信号重塑为数字信号的技术。脉冲编码调制具有良好的信噪比。对于传输通道,脉冲编码调制比 DPCM 需要更高的带宽。
PCM方法分为3个部分,最初是供给端的传输,传输路径的二次再生以及接收端。
这些步骤如下图所示:
差分脉冲编码调制 (DPCM):
DPCM 与用于将模拟信号重构为数字信号的 PCM 技术相同。 DPCM 具有中等信噪比。
DPCM 不同于 PCM,因为它量化了特定样本和预期价格的区别。这就是它被称为差分 PCM 的解释。
DPCM 发送器和 DPCM 接收器的操作如下图所示:
让我们看看PCM和DPCM之间的区别,如下所示:
S.NO | PCM | DPCM |
---|---|---|
1. | PCM stands for Pulse Code Modulation. | While DPCM stands for Differential Pulse Code Modulation. |
2. | In PCM, feedback is not provided. | While in DPCM, feedback is provided. |
3. | It has good signal to noise ratio. | While it has moderate signal to noise ratio. |
4. | It is less efficient than DPCM. | While it is more efficient than PCM. |
5. | For transmission channel, PCM needs high bandwidth(B). | Whereas DPCM needs less bandwidth(B) than PCM. |
6. | PCM is complex than DPCM in terms of complexity. | While DPCM is simple in terms of complexity. |
7. | In PCM, seven bits are transmitted per eight sample. | In DPCM, four bits are transmitted per six sample. |
8. | In PCM, for transmitting bits rate varies from fifty five to sixty four. | While in DPCM, for transmitting bits rate varies from thirty two to forty eight. |