Ray-tracing Based Channel Clustering and Analysis at 28 GHz in Conference Environment

The millimeter-wave (mm-wave) band is of great importance for the future wireless communication systems. Studies on millimeter-wave channels are of great importance to mmwave wireless technologies. In this paper, we investigate the 3-D clustering phenomenon of mm-wave propagation at 28 GHz in a conference room. The results including cluster propagation mechanisms, the relationship between the clusters and the physical environment, and intra-cluster statistics are presented. Results show that the cluster propagation mechanisms are influenced by the room geometry. The last hop of sub-paths in the same cluster may locate on different objects existing in the environment. Besides, cluster statistics including intra-cluster delay spread (DS), angle spread (AS), and sub-paths number are discussed. Their logarithms fit normal distributions well. These results could help extend and justify current research on mm-wave channels. Moreover, a ray-tracing (RT) tool is used to emulate the measurements and similarity results are presented and analyzed. Excellent agreements between the measurement and simulation verify the feasibility and accuracy of RT simulation for studying the cluster characteristics.