| 摘要 |
PURPOSE:To safety and easily inform a vehicle crewman about a fact that a vehicle goes into a communicatable area of a base station by a carrier wave receiving means from the base station by detecting a car speed, in a PHP system. CONSTITUTION:A car speed signal detected by a car speed sensor 26 is inputted to a CPU 22, and whether a car speed is below a prescribed car speed or not is decided. The CPU 22 receives a receiving signal converted to an intermediate frequency signal by a mixer 40 of a receiving part 14 through a demodulating part 42 and a TDMA processing part. The CPU 22 monitors a control carrier in the receiving signal, and decides whether a vehicle exists in a communicatable area of a base station or not in advance before a communication to the base station is started. In the case it exists in the area, a base station search processing is executed, and also, its fact is informed to a vehicle crewman. |
