Investigation of Orthogonality of Multi-User Channels Using 73 GHz Statistical Channel Models

Abstract

This paper focuses at the investigation of the degree of orthogonality or spatial separation of multiple users in a densely populated shopping mall scenario. For this purpose, we have used well known millimeter wave (mmWave) channel models and developed a statistical MIMO enabled channel simulator. We have analyzed the mutual orthogonality of the multi-user channels by changing the number of multipath clusters, base station (BS) antennas and inter antenna element distance. Our analysis shows that current channel models result in mmWave channels which are highly correlated in space and spatial separation of users is quite difficult. Increase in the number of multipath clusters, antenna spacing and the number of antenna elements reduce the spatial correlation of users but up to a certain extent and beyond that spatial separation is bottlenecked.