Patent ID: 9225567
Filing Date: 2015-12-29
Classification: H04L

Abstract:
1. A receiving apparatus comprising: a receiver that simultaneously receives a plurality of signals on a plurality of channels, which have been modulated using frequency shift keying (FSK); a calculation range controller that detects a Mark frequency and a Space frequency for each channel, controls and determines for each channel a frequency range for Fourier transformation calculation of the plurality of receiving signals, based on the detected Mark frequency and the detected Space frequency; a frequency component detector that performs the Fourier transformation calculation on the determined frequency range for each channel and detects, for each channel, frequency components of the plurality of receiving signals respectively; a channel shifter that shifts for each channel a central frequency of the detected frequency components to a predetermined reference frequency; and a demodulator that demodulates the shifted frequency components of each channel and extracts demodulation data for each channel, wherein the calculation range controller detects a frequency that has a peak value in a reception level among positive frequency components of the plurality of receiving signals as the Mark frequency and another frequency that has a peak value in the reception level among negative frequency components of the plurality of receiving signals as the Space frequency.