Patent ID: 7492836

Claim:
A wireless data communication demodulation device which receives and demodulates a transmission packet having a first half that includes a frequency shift keying modulating signal and a second half that includes a phase-shift keying modulating signal, the wireless data communication demodulation device comprising: an FSK demodulation unit for demodulating the frequency shift keying modulating signal; and a PSK demodulation unit for demodulating the phase-shift keying modulating signal, wherein: the FSK demodulation unit includes: discriminating means for generating a voltage signal based on a frequency signal that includes the transmission packet; comparing means for generating FSK demodulated data based on the voltage signal; and frequency error detecting means for detecting a frequency error of the frequency shift keying modulating signal; the PSK demodulation unit includes a demodulation circuit in the form of a phase locked loop; and a frequency error detection value detected by the frequency error detecting means is set as an initial value of the phase locked loop.