ON-VEHICLE BEACON RECEIVER AND ON-VEHICLE NAVIGATION SYSTEM

摘要

PURPOSE:To improve the reliability of beacon position detection by comparing the phases of an AM demodulation signal and a 1kHz clock generated inside, detecting a phase inversion position and deciding that a vehicle is just under a beacon on a road. CONSTITUTION:The output of an AGC voltage generating part 2 is inputted to an AGC amplification part control signal generating part 19 and the output is inputted through an A/D conversion part 3 to a reception control part 6. The reception control part 6 decides whether or not transmitted signals from the beacon on the road are displayed at a display part 7 with the A/D converted AGC voltage as a reference. Further, the reception control part 6 detects the phase inversion of a position detection signal by comparing the phases of the AM demodulation signal from a wave form reshaping part 5 and the 1kHz clock generated inside. At this time, when the phase inversion is detected consecutively for N periods, it is decided that the vehicle is just under the beacon. Thus, the reliability of the beacon position detection can be improved.