Dynamic Traffic Information Distribution Technology

ITS, the abbreviation of Intelligent Transportation System, is a system consisted of information technology, communication network, vehicle positioning, intelligent analysis and routing, aiming at reducing traffic jams and accidents, which makes life more convenient and comfortable. ITS technology is of great practical and theoretical importance in solving traffic and environmental problems caused by city's fast and excess developmenta, helping to guarantee traffic safety, enhance transportation efficiency, accelerate economic development, improve people's life quality, and promote world's information industry.Transportation Information Platform serves as the basic information platform for Intelligent Transportation System. Based on Geographic Information System for Transportation (GIS-T) and dynamic traffic status, transportation Information Platform can provide accurate traffic information of traffic control, traffic information management and vehicle navigation. Traffic Information Distribution System is the foundation of the whole traffic information sharing platform, which can provide accurate, real-time traffic information service by broadcasting information about vehicle navigation, current traffic state, dynamic traffic flow analysis, danger alarm and emergency message. It also distributes traffic guiding to vehicle drivers to make their transportation more secure, efficient and convenient. Traffic Information Distribution is one of the basic and key technologies of Intelligence Transportation System.With the discussions of the framework of City traffic information system and basic theories of traffic information distribution technologis, this paper briefly analyzes and compares the essential features of several key wireless data communication technologies used in ITS. Secondly, we put forward a new solution in distributing traffic information based on FM multiplex broadcasting technology. The functional structure of the application applying Data Radio Channel (DARC) Protocol is presented. Concerned of the method proposed above, we describe the procedure of both hardware and software design in detail. The realizations of all central modules and peripheral circuits are discussed specifically. In this thesis, we focus on our research in the following areas: frame synchronization, data formatting, error protection and scrambling, Level-controlled Minimum Shift Keying modulation, mixed signal sending and receiving, signal filtering and demodulation, MSK demodulation, data decoding and recovery. Moreover, a prototype of traffic information distribution system using FM multiplex broadcasting technology is developed. The practical experiemental result shows the solution is feasible with a good expansibility, which can potentially offer many advantages such as mobile reception, large service area, low system introduction cost, and excellent performance.