Measurement and Diffuse Multipath Analysis of V2V Propagation Channel at 5.9 GHz in Tunnel Area

Vehicle-to-vehicle (V2V) communication is an essential fundament of intelligent transportation systems (ITS). Therefore, evaluating the influence of the radio propagation channel of ITS is of great interest. So far the diffuse multipath in V2V propagation channel in tunnel area has not been thoughtfully studied. This paper presents channel measurements and analysis of V2V channel characteristics at 5.9 GHz in tunnel. We evaluate and compare the received power and root mean square (RMS) delay spread for outside and inside tunnel. Further, we use the space-alternating generalized expectation-maximization (SAGE) based channel parameter estimator with the autoregressive (AR) filter to estimate the specular and the diffuse multipath components. Results reveal that the diffuse multipath inside tunnel is not dominant in the line-of-sight (LoS) case. The ratio between the diffuse multipath component (DMC) power and the total received power has a mean value of 5.61% and a standard deviation of 6.27%.