Investigation of MPC Correlation and Angular Characteristics in the Vehicular Urban Intersection Channel Using Channel Sounding and Ray Tracing

This paper examines the multiple-input multiple-output (MIMO) characteristics of the vehicular MIMO channel at 5.9 GHz by analyzing the correlation of multipath components (MPCs) in the case of high antenna separation and the angular characteristics of the same scenario. The scenario is selected as crossing traffic on urban intersections. The 2 × 2 channel measurements with a wideband channel sounder are employed for the correlation analysis, and in parallel, the same scenario is simulated with a ray-tracing tool for the analysis of the angular domain. We introduce measures and tools to describe the relevant characteristics and the performance; the limitations of the ray-tracing simulation are also subdued to critical evaluation. The focus of this paper is set on the evaluation of the presented method on one selected experiment (combination of measurement and ray-tracing simulation) rather than on an exhaustive statistical analysis of many scenarios. The combination lies in the higher level of analyzing the MIMO characteristics of the channel using two different methods. The results provide that the MIMO channels show a similar power level in terms of mean MPC power, but the linear correlation stays relatively low. Specifically, discrete MPCs tend to be more highly correlated than diffuse MPCs. Furthermore, the angular spread is highly dynamic but small and substantially increases when both vehicles are near the center of the intersection. Significant power contributions caused by buildings along the roadside are identified.