A Novel Spatially Correlated Multiuser MIMO Channel Modeling: Impact of Surface Roughness

A novel approach for modeling multiuser multiple-input and multiple-output (MIMO) channels is proposed. Here, the scatterers are modeled as random rough surfaces: Any point on rough surfaces scatters the incident wave into any given direction with certain probability. This leads to correlation across different spatially distributed users. The paper derives closed form expressions for the intra-user (point-to-point) and inter-user (multiuser) correlation of pair-wise channel coefficients. It is observed that the distance of users relative to the scatterer surfaces as well as the degree of roughness impact the correlation region. The technique is applied to both non-line-of-sight (NLOS) and line-of-sight (LOS) scenarios. It is observed that LOS signals drastically boost the correlation of the channel coefficients.