# Questions tagged [dpcm]

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### What is the need for prediction filter in PCM and DPCM?

The DPCM works by the difference between actual samples and predicted samples. If we already have the actual samples, we can quantize it and encode it later. But why we use prediction filter? And ...
282 views

### A problem about SQNR, PCM, DPCM, and DM

A baseband analog message signal $x(t)$ with bandwidth 20 kHz, power $10^{-3}$, and $|x(t)| \leq 1$ is waveform encoded and transmitted through a channel of bandwidth 160 kHz. Besides, let the sampled ...
536 views

### Differential Pulse Code Modulation (DPCM)

In the following figure we see an encoder and a decoder of a Delta Modulation System, which is a simple DPCM System with a 1-bit quantizer: We assume that signal $x(n)$ is known, that $\hat{x}(-1)=0$ ...
• 285
1 vote
47 views

### What is the rationale for division by 8 during ADPCM audio compression?

I am studying ADPCM and while I understand the concept I cannot find an explanation for some of the calculations in available implementations such as the one outlined here: ...
• 11
1 vote
956 views

### DPCM Encoder and Decoder Simulation in MATLAB

I am trying to simulate DPCM in order to understand how it works. I am trying to implement the simplest version of DPCM which has a system scheme like in figure 1. Sorry for the quality of the ...
• 195
1 vote
555 views

### Is the incoming sample in a standard DPCM already quantized?

I began learning about DPCM and i've got one issue I am not sure about: Is the incoming sample m[k] (see image for reference) already quantizied or not? I think it is but with an (assumed) very fine ...
What are the definitions of symbols and samples related to PCM? For example in binary encoding $\{0,1\}$ with 8 levels of quantization, is one symbol either of $\ 0 \ or \ 1\$? or is it the ...