Frequency shift keyed demodulator

摘要

This invention relates to a demodulator for an FSK signal having a baud rate which is independent of the signal's bandwidth. The demodulator multiplies the received FSK signal with two quadrature signals having a frequency which lies between the two frequencies of the FSK signal, to obtain the real and imaginary components of a phasor. The phasor rotates in the complex plane, the direction of the rotation depending on whether the frequency of the quadrature signals is above or below the frequency of the received signal. The demodulator determines the direction of rotation of the phasor and generates binary data corresponding to the frequency change in the FSK signal.