Receiving apparatus and demodulation method

摘要

A frequency range for Fourier transform is controlled and a digital signal is subjected to fast Fourier transform within the controlled range, whereby a plurality of frequency components (FFT signals) in the digital signal are detected. A transmission rate of a received signal is determined using the detected FFT signals and the FFT signals are demodulated by an operation at a speed corresponding to the determined transmission rate.

主权项

1. A receiving apparatus that receives and demodulates a frequency shift keying (FSK) modulated signal that is transmitted at a transmission rate selected from a plurality of transmission rates with different bandwidths, the receiving apparatus comprising:
a calculation range controller that controls a frequency range used for detecting a frequency component, on the basis of a Mark frequency and a Space frequency; a frequency component detector that detects a frequency component in the FSK modulated signal, on the basis of the controlled frequency range; a mode determiner that determines the transmission rate of the FSK modulated signal, on the basis of the detected frequency component; and a demodulator that operates at a speed corresponding to the transmission rate and demodulates the detected frequency component.