Non-coherent FSK demodulator and demodulating method

摘要

A non-coherent frequency shift key demodulator, which includes a digital limiter and a decision logic circuit is disclosed. The digital limiter is used for receiving a baseband signal with a digital signal conveyed therein and comparing the baseband signal with a reference level in order to output a frequency-modulated rectangular pulse. The decision logic circuit, coupled to the digital limiter, is used for receiving the rectangular pulse and counting the transformation of the rectangular pulse to obtain a cycle period, wherein the cycle period is compared with a threshold value to determine the digital signal carried in the baseband signal.