Shadowing Characterization for 5-GHz Vehicle-to-Vehicle Channels

Abstract

As one of the most important parts of intelligent transportation systems, vehicle-to-vehicle (V2V) communications have been widely studied because of the potential improvements it can provide in terms of traffic efficiency and traffic safety through various applications. The research on propagation characteristics for V2V channels is of primary importance, and one particular significant topic is shadowing effects induced by obstructing vehicles between transmitter (Tx) and receiver (Rx). In this paper, we present shadowing measurement results for V2V channels in both urban and highway scenarios, in which a truck and a van were used as the obstacles. Channel measurements in the 5-GHz band were performed in both line-of-sight (LOS) and non-LOS (NLOS) conditions, and different relative positions of vehicles on the road were considered. Based on the measured results, statistics for the shadowing loss and the root mean square delay spread (RMS-DS) are provided, and shadowing effects in each case are compared. By utilizing the temporal power delay profile correlation coefficient, the stationarity distance for each case is estimated, and the nonstationarity phenomenon and its relation to the shadowing effect are investigated. The mean value of shadowing loss was found to range from 3.38 to 9.33 dB with standard deviation ranging from 3.20 to 6.98 dB, and a normal distribution can well describe the statistics of the shadowing loss. With smaller RMS-DS values, the highway shows larger shadowing losses than the urban street. Moreover, in any specific scenario (e.g., highway or urban), the shadowing effect is generally closely related to the RMS-DS and stationarity distance: Larger shadowing loss always occurs when RMS-DS is large and average stationarity distance is small.