| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To facilitate detection of a phase change corresponding to train control information of an ATC signal transmitted from the ground side to an on train side. <P>SOLUTION: A phase detection means that detects a phase of a carrier wave of an amplitude modulated signal transmitted from ground equipment and outputs phase information is composed by including: an A/D converter 31 that samples amplitude modulated signals by a prescribed interval; a digital correlator 32 that calculates a correlation value between the carrier wave and a basic carrier wave in each signal part of amplitude modulated signal that is intermittent based on sampling data output from the A/D converter 31; and a phase difference detection circuit 33 that detects the correlation value maximum position of each signal part intermittent based on the correlation value calculated by the digital correlator 32, detects the relative phase difference of the carrier wave between the signal parts adjoined from the difference of the correlation value maximum position between signal portions mutually adjoined and outputs the phase information based on the detected phase difference. <P>COPYRIGHT: (C)2013,JPO&INPIT</p> |
