VEHICLE COMMUNICATION DEVICE

摘要

[Problem] To provide a vehicle communication device that can determine with high precision whether or not a measurement signal received by a moving device is a normal signal. [Solution] The moving device receives a 100% duty measurement signal transmitted from a vehicle-mounted device. The reception strength of the received measurement signal is divided into time units (ta), and the average value of the reception strength for each time unit (ta) is determined. The maximum value (Amax) and minimum value (Amin) for the average value are determined, and the ratio between the maximum value (Amax) and minimum value (Amin) is transmitted to the vehicle-mounted device as signal strength fluctuation information. The vehicle-mounted device determines that the communication state is abnormal if the fluctuation ratio is determined to exceed a predetermined threshold.