| Vehicle holding has been increasing along with the development of national economy. According to statistics, vehicle holding in China has reached 177 million by the end of July 2009. Solutions of various transportation problems brought by the vehicle boost have been brought to social focus. Techniques such as automation, signal processing, computer, detection and communication-electronics have been widely exploited in various fields, and this paper focuses on the application of these modern techniques for Intelligent Transportation System (ITS). In 2004, Dr. Fenghao Mu proposed a novel ITS acquisition system, as well as its major functions and implementation of key techniques.It is proposed that transportation information is acquired by RFID techniques. Thus the monitoring and administration of vehicles is implemented by the communication among BS and electronic tags on the vehicles. This paper focuses on one key function of searching and positioning of vehicles in rural areas. Since there is no fixed BS in rural areas, mobile BS has to be applied for vehicle searching. This paper proposed an overall plan of one BS positioning system, with antenna array to receive signals. The positioning is then implemented by a series of processing of the received signals.The main work of the paper includes:(1) Estimated the distance of the target vehicle considering the characteristics of signal propagation in space with existing channel attenuation model and match filter method.(2) Estimated the DoA with ESPRIT algorithm making use of the characteristics antenna array, analyzed the DoA precision relative to antenna array characteristics, and proposed an antenna model that fits the application.(3) Analyzed the Hopfield NN theory, designed a Hopfield NN model for calculating eigenvalue, analyzed its feasibility, and applied it in ESPRIT algorithm.(4) Conducted simulation experiments. The results show that the scheme proposed in this paper is able to implement precise positioning of vehicles.
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