1. PCM (Pulse Code Modulation)

2. Modulation
Modulation is the addition of information (or the signal) to an electronic or optical signal carrier.

3. Types of Modulation

4. Analog Signal

5. Digital signal

6. PCM
Analog signal is converted into digital signal by using a digital code.
It is the standard form of digital audio in computers, Compact Discs, digital telephony and other digital audio applications

7. Continued…
The analog signal is first sampled at a 8-kHz sampling rate. Then each sample is quantized into 1 of 256 levels and then encoded into digital eight-bit words.

8. Sampling

9. Quantization

10. Encoding

11. PCM