Pulse modulation is a process that takes periodic samples from an analog message signal and converts them into binary codes. There are two main types of sampling: natural sampling, which follows the actual shape of the message signal, and flat top sampling, which only takes samples during the positive pulse and maintains the same level during the negative pulse. Common pulse modulation techniques include PAM, which varies the amplitude of a pulse carrier signal; PWM, which varies the width of a pulse carrier signal; and PPM, which varies the position of a pulse carrier signal. Samples are then converted to binary codes through quantization and rounding off.

1. PULSE MODULATION

2. Definition
Process of taking samples periodically and
converting them into binary codes
Sampling
Process of taking samples periodically from
analog message signals

3. Types of Sampling
• Natural Sampling
• Flat Top Sampling

4. Natural Sampling
It follows the actual shape of the message
signal

5. Flat Top Sampling
It takes samples only during +ve pulse does
not take sample during –ve pulse
Same level is maintained during –ve pulse

7. PAM
 Amplitude of the pulse carrier signal is varied according to the amplitude of the
message signal
 Same like Natural Sampling

8. PWM
 Width of the pulse carrier signal is varied according to the amplitude of the
message signal

9. PPM
 Position of the pulse carrier signal is varied according to the amplitude of
the message signal

10. PCM
 Samples are converted into binary codes

11. Quantization – Rounding Off