Frequency shift keying (FSK) is a modulation method that transmits digital information by changing the frequency of the carrier. The main technical specifications of FSK include the following aspects:
Working principle: FSK uses baseband pulse signals to control the frequency of analog carrier signals so that it changes with the changes of baseband pulses. Two frequencies f1 and f2 are usually used to represent binary "0" and "1" respectively.
Anti-interference ability: FSK has strong anti-noise and anti-attenuation capabilities, which makes it widely used in medium and low-speed data transmission.
Implementation difficulty: FSK technology is relatively simple to implement and easy to modulate and demodulate.
Spectrum utilization: FSK has moderate spectrum utilization and can transmit information within a limited bandwidth, but its spectrum utilization is lower than other modulation methods such as PSK.
Application field: FSK is widely used in wireless communication, data transmission and other fields, such as radio broadcasting, remote control, etc.
Phase characteristics: According to the carrier phase characteristics at the symbol conversion time, frequency modulation is divided into discontinuous phase FSK and continuous phase FSK. Discontinuous phase FSK uses a unipolar non-return-to-zero code to key two independent carrier oscillators to generate a phase-discontinuous FSK signal; while continuous phase FSK uses a baseband signal to frequency modulate a voltage-controlled oscillator (VCO) to generate a phase-continuous FSK signal.
