COMMUNICATION SYSTEM BETWEEN ROAD AND VEHICLE

摘要

PROBLEM TO BE SOLVED: To suppress the extension of power distribution on a road and to surely avoid communication with an on-vehicle radio equipment of a vehicle running on an adjacent lane by composing plural beams different in beam direction and beam width. SOLUTION: Two or more beams different in beam direction in a running direction 3 on a lane set in a communication area and different in beam width in a lane direction 4 orthogonal to the running direction 3 are composed by a road equipment antenna system 7 including plural element antennas and a feeder circuit. Thereby a composite beam radiated from the system 7 constitutes a communication boundary 10 in which power distribution on the road is suppressed in the lane direction 4 independently of the expected angle η 16 of the system 7 and a no-response boundary 11. Namely an on-vehicle radio equipment 6a loaded on a vehicle 5a running on the lane 1a acts as a road- vehicle communication system capable of surely communicating with the system 7 in an area surrounded by the boundary 10.