Modified spatial channel model for MIMO wireless systems

Abstract

The third generation partnership Projects (3GPP) spatial channel model (SCM) is a stochastic channel model for MIMO systems. Due to fixed subpath power levels and angular directions, the SCM model does not show thedegree of variation which is encountered in real channels. In this paper, we propose a modified SCM model whichhas random subpath powers and directions and still produces Laplace shape angular power spectrum. Simulationresults on outage MIMO capacity with basic and modified SCM models show that the modified SCM modelgives constantly smaller capacity values. Accordingly, it seems that the basic SCM gives too small correlationbetween MIMO antennas. Moreover, the variance in capacity values is larger using the proposed SCM model.Simulation results were supported by the outage capacity results from a measurement campaign conducted inthe city centre of Oulu, Finland.