| 摘要 |
PURPOSE:To reduce the size of an information receiver for a vehicle by providing a common data processing circuit for processing an output signal of a road side beacon (GSP satellite) when it is judged that the level of radio wave of a road side beacon is higher (lower) than a reference value. CONSTITUTION:A data processing circuit 17 detects the current position of a vehicle by inputting a GPS Signal, detects installation position information of a road side beacon obtained from a phase detecting circuit 22, detects information for a vehicle from the beacon obtained from a data demodulating circuit 21, and transmits the same to a navigation controller 9. A level detecting circuit 20 compares a received radio wave level of the beacon with a reference value so as to examine whether the vehicle enters the communication range of the beacon or not. The circuit 17 receives the output of the circuit 20, and when it is judged that the radio wave of the beacon is strong, the condition of position detection by using software for GPS is changed to software for conducting position detection by using a beacon signal. That is, either radio wave of the beacon or that of the GPS satellite is given the priority to be processed by one circuit 17. |
