Core Concepts
Why DPCM?
Standard PCM encodes the absolute value of each sample. However, most real-world signals (like audio or video) change slowly between samples. DPCM exploits this correlation. Instead of encoding the sample value, we encode the difference between the actual sample and a predicted value.
The Predictor
The heart of DPCM is the predictor. It uses past reconstructed samples to guess the current sample. A simple predictor is:
x̂(n) = x̂(n-1)
This assumes the next sample is roughly the same as the previous one.
DPCM Transmitter Block Diagram
Interactive Lab
Signal Power
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Quantization Noise
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SNR (Quality)
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Quantization Calculator
System Parameters
Maximum SNR
Formula used:
SNR ≈ 6.02n + 1.76 (dB)