ITPEC FE Morning October 2023 Question 24

PCM (Pulse Code Modulation) — identify the sampling stage in the PCM pipeline.

PCM converts analog audio to digital in three ordered steps:

• •Sampling — capture analog signal values at regular time intervals
• •Quantization — round each sampled value to the nearest discrete level
• •Encoding — convert quantized values into binary code

The question asks about "capturing analog values at a regular interval," which is sampling.

Why not others:
- (a) Encoding — final step; converts quantized values to binary
- (b) Reverse quantization — part of decoding, not encoding
- (c) Quantization — rounds sampled values to discrete levels, does not capture them

Key rule: PCM order is S → Q → E: Sample first, Quantize second, Encode last.

AI-generated — may contain errors