Research And Design Of Vehicle Monitoring System Based On CDMA

Recently, there has been more focus on the application research of wireless communication networks. How to utilize existing networking resources and realize the monitoring of moving object with low cost have been the key issues. CDMA networks can utilize its own unique characters, the strict synchronization between end-devices and net clocks, to realize the location services without the help of GPS system. So the location and monitoring information transferring both can be realized by CDMA networks.This paper introduces the structure for vehicle monitoring system based on CDMA networks, analyses the software and hardware design of monitoring center and the end-devices inside the car. It also presents lots of in-depth research in system design, such as video transportation, concurrent scheduling strategy and intelligent processing of monitoring center.The streaming media has the character of big volume and higher requirement of real-time and reliability. However, the limited upload bandwidth of CDMA networks causes the difficulty for video stream transportation. In order to effectively transfer the video stream with high quality, it needs many technique supports. Based on the comparison and analysis of various data compression standard, this paper chooses MPEG-4 as the video compression standard. Then, it analyses the transportation strategies of video stream, chooses self-adaptive coding plan and discusses the QoS strategy of end-devices.In the process of CDMA vehicle monitoring, the monitoring center will receive large amount of information from different end-devices and the information is correspondent to different events. The monitoring center needs to make the real-time responses according to different event received, which is the most important part for the whole system. Based on the concurrent processing performance analysis of monitoring system, this paper proposes a prior queue algorithm to realize the concurrent scheduling strategy of CDMA vehicle monitoring system and demonstrates how to realize this algorithm.The time of the event processing in CDMA vehicle monitoring system can be divided into three parts: end-device processing time, information transportation timeand monitoring center processing time. For the limitation of the data transportation rate of the CDMA system, information transportation time take a large part of the whole processing time. So the improvement of the hardware of end-device and monitoring center will not improve the event processing time of the monitoring system. For this problem, this paper proposes an intelligent event processing to improve system's concurrent processing capability and demonstrates the design of knowledge database and reasoning machine of event intelligent processing mechanism.