| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a wireless communication system which shortens time required for synchronous acquisition rather than in the prior art to improve responsiveness when communication is performed by a spread spectrum system. <P>SOLUTION: A sliding correlator (or matched filter) does not immediately start trial of the synchronous acquisition and waits for a synchronous point retrieval start control signal from a CPU even when it becomes a state in which the trial of the synchronous acquisition can be started at a point of time t2 by starting reception of an actual receiving signal at a point of time t1 by an onboard unit for RF reception. Then, when the synchronous point retrieval start control signal comes at a point of time t3, to a point of time t4 when the synchronous point retrieval end control signal comes is used as a retrieval period, and the trial of the synchronous acquisition is started for a period where there is a starting point in the retrieval period. As a result, the synchronous acquisition is successful at a point of time t5 when the receiving signal using the time t3 as the starting point is received for one period, despreading demodulation is performed after that. <P>COPYRIGHT: (C)2010,JPO&INPIT |
