IN-VEHICLE RADIO COMMUNICATION DEVICE, PORTABLE COMMUNICATION INSTRUMENT, AND RADIO COMMUNICATION SYSTEM

摘要

PROBLEM TO BE SOLVED: To obtain an in-vehicle radio communication device etc., capable of rapidly determining the whereabouts of a portable communication instrument, for use in smart entry.

SOLUTION: This in-vehicle radio communication device comprises antennae 1A and 1D. A transmission signal SLF1A transmitted from the antenna 1A has a radio communication range 2A which includes an external area 2AE of a vehicle 10 and an in-vehicle area 3 thereof. A transmission signal SLF1D transmitted from the antenna 1D has a radio communication range 2D which includes an external area 2DE of the vehicle 10 and the in-vehicle area 3 thereof. In the radio communication ranges 2A and 2D, an overlap area is not provided between the external areas 2AE and 2DE outside the vehicle 10; and the in-vehicle areas 3 of the vehicle 10 overlap each other as a common internal area. The transmission signals SLF1A and SLF1D are simultaneously transmitted from the antennae 1A and 1D.

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