FSK (Frequency Shift Keying)
Definition
Frequency Shift Keying (FSK) is a digital modulation technique where digital information is transmitted through discrete frequency changes of a carrier signal while maintaining constant amplitude.
Detailed Explanation
Working Principle
- Binary 1: Higher frequency (f1)
- Binary 0: Lower frequency (f0)
- Amplitude remains constant
- Phase continuity maintained at bit transitions
Types of FSK
-
Binary FSK (BFSK)
- Uses two frequencies
- Simplest form of FSK
- Common in low-speed applications
-
Multiple FSK (MFSK)
- Uses multiple frequencies
- Higher data rate
- More complex implementation
Applications
- Amateur radio
- Emergency broadcasts
- Low-frequency radio navigation
- Digital telephony
Advantages & Limitations
Advantages:
- Better noise immunity than ASK
- Less susceptible to amplitude distortion
- Simple demodulation
Limitations:
- Requires more bandwidth than ASK
- More complex than ASK
- Sensitive to frequency distortion