New Approach to Enhance and Evaluate the Performance of Vehicle-Infrastructure Integration and Its Communication Systems

摘要

Initial research studied the use of wireless local area networks (WLAN) protocols in Inter-Vehicle Communications (IVC) environments. The protocols performance was evaluated in terms of measuring throughput, jitter time and delay time. This research has developed a unique setup to evaluate IEEE802.11 protocols. This setup will reduce the cost of test beds that might be deployed to evaluate the performance of new IEEE802.11 protocols. To validate the concept, researchers have implemented the test bed at University of Detroit Mercy and evaluated the performance of IEEE802.11b/g. The developed WLAN-based test bed allows the testing of different IEEE802.11 protocols and yet keeps the cost at a reasonable level. Researchers investigated the impact of Doppler shift on the quality of the transmitted/received signal in an Orthogonal Frequency Division Multiplexing (OFDM) communication system. The developed channel model that combines Additive White Gaussian Noise (AWGN) and Rayleigh channel representations to resemble a realistic transmission medium is presented. The model is validated by showing that the relation between Energy of Bit to Noise Ratio (Eb/N0) and Bit Error Rate (BER) is consistent with theoretical formulas. The degradation in signal quality as a result of increased vehicle speed is presented through graphical and analytical representation of BER with respect of applied Doppler shift. Moreover, a new methodology to reduce the impact of Doppler shift is proposed and simulations are performed to confirm the reduction of Doppler shift impact on the signal quality.