Design And Implementation Of A Dynamic Traffic Information Acquisition System

Nowadays, Traffic jam is a problem in many cities. Intelligent Traffic System (ITS) is a key to the problem. Many people engage themselves in ITS. This paper gives the description on Intelligent Traffic System first. Then it designs a dynamic traffic information acquisition system, which is a sub-system of ITS.This paper put emphasis on the RF communication between base station and plate. This paper divide the job into 3 parts.The first part is the specification of the RF communication protocol, which is outlined in Dr. Mu's paper. It's based on the well known slotted-ALOHA, which is a member of the ALOHA protocol. This paper analysis the performance of both slotted-ALOHA and ALOHA protocol. Then give the definition of the frame structure, data structure and error control mechanism.In the second part, an experiment system is designed to verify the communication protocol. The experiment system is combined with 2 modules, RF communication module and digital base band signal processing module. This paper designed the latter based on an Aletra's Cyclone family FPGA. The design issues of the Cyclone family FPGA are discussed, such as power supply, configuration and the board layout.In the third part, the protocol is implemented in an FPGA. In this part, analyze the structure of base station and plate, and give their implementations. the serial communication module, CRC checksum generation module and synchronization module are discussed in detail. This paper also discuss some techniques in FPGA design such as synchronizing clock and parallel data bus.