Modulation and Demodulation
Definition
Modulation is the process of varying one or more properties of a high-frequency carrier signal according to the instantaneous value of the input signal. Demodulation is the reverse process of extracting the original signal from the modulated carrier wave.
Detailed Explanation
Modulation Types
-
Amplitude Modulation
- Varies carrier amplitude
- Simple but noise-sensitive
- Used in AM radio
-
Frequency Modulation
- Varies carrier frequency
- Better noise immunity
- Used in FM radio
-
Phase Modulation
- Varies carrier phase
- Complex but efficient
- Used in digital communications
Demodulation Methods
-
Detection
- Envelope detection for AM
- PLL detection for FM
- Coherent detection for PM
-
Signal Recovery
- Filtering
- Amplification
- Error correction
Applications
- Radio broadcasting
- Television
- Mobile communications
- Satellite communications