Effect of fading correlation in relay assisted cooperative SIMO system

In this paper we investigate the impact of fading correlation at the receiving elements of a compact antenna array in a relay assisted cooperative scheme in single-input multiple-output (SIMO) configuration with one or multiple relays operating in amplify-and-forward mode. We assume that the source and the relay terminals are each equipped with one antenna, while the destination terminal is equipped with M antennas. Here, we consider a model of local scatterer around the transmitting/relay nodes and a realistic angular power profile, the Gaussian angle of arrival (AOA) distribution, is assumed. The received multipath signals arrive within a given angular spread, and the spatial cross-correlation is obtained by simulation, taking account of the array configuration and propagation environment parameters i.e. antenna spacing, AOA and angular spread. The results illustrate lower fading correlation in a relay based SIMO system as compared to SIMO system without relay, with the dependence of fading correlation on the positioning of the relay nodes and its sensitivity to the angular spread of the arrived signals from the transmit/relay nodes.