DRIVE DIRECTION DETECTION SYSTEM IN ROAD-VEHICLE COMMUNICATION SYSTEM

• Main Author: ARAKI TADASHI
• Format: Patent
• Language: English
• Published: 24.04.1998
• Edition: 6
• Subjects: ANALOGOUS ARRANGEMENTS USING OTHER WAVES; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; ELECTRIC COMMUNICATION TECHNIQUE; ELECTRICITY; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION ORRERADIATION OF RADIO WAVES; MEASURING; PHYSICS; RADIO DIRECTION-FINDING; RADIO NAVIGATION; TESTING; TRANSMISSION; WIRELESS COMMUNICATIONS NETWORKS

PROBLEM TO BE SOLVED: To allow a vehicle side to detect a drive direction by assigning repetitively at least three frequencies in a prescribed sequence as carrier frequencies in a series of cells formed on a road and allowing the vehicle side to recognize a pattern of a change in a reception frequency during driving so as to utilize a difference from the frequency and a spread code. SOLUTION: In this driving direction detection system, transmitters 1 with different carrier frequencies are placed to each position of a road to form consecutive cells 3 on the road. Each transmitter 1 is connected to a control station of a road manager via an optical fiber or a coaxial cable. Frequencies f1,f2,f3 are assigned to each transmitter 1 in the installed sequence among a prescribed frequency bands in the order of f1, f2, f3, f1, f2, f3,... repetitively. A difference between adjacent frequencies is decided depending on an occupied band width per one channel stipulated by a transmission speed.