Patent ID: 7443342

Claim:
A reception time determining apparatus which measures the reception time of a transmission signal from a transmitter, wherein said transmission signal is a signal which produces a demodulation signal in which a signal change portion is unevenly distributed on a time axis and the waveform thereof is continuous on the time axis, said apparatus comprising: a demodulation section which demodulates a reception signal and outputs said demodulation signal; a signal change portion detection section which detects said signal change portion contained in said demodulation signal which is output from said demodulation section, and outputs a signal change portion detection signal; and a first time measurement section which measures a reception time of said reception signal based on said signal change portion detection signal output from said signal change portion detection section, wherein said signal change portion detection section comprises a band pass filter configured to pass at least one portion of frequency components contained in said signal change portion and to inhibit frequency components comprising a main lobe of the power spectrum of said demodulation signal, and wherein said first time measurement section measures said reception time based on an output signal of said band pass filter.