Performance analysis of repetition-based decode-and-forward relaying over asymmetric fading channels

This paper analyzes the outage probability of cooperative communications over asymmetric fading environments. This work investigates the scenario where cooperative nodes are located at different geographical locations. Some cooperative nodes experience line of sight (LOS) signals and some nodes may experience non-LOS (NLOS) signals. As a result, signals in different links are affected by different fading distributions, one link may undergo Rician fading distribution and others links may undergo Rayleigh fading distribution. Such scenario is referred to as asymmetric fading channel. Assuming decode-and-forward, we provide an analytical model of outage probability for repetition-based relaying over different asymmetric fading channels. We show that the outage performance is better when the relays are in LOS situation with respect to the source rather than to the destination for the large number of relay nodes regime. The conclusions are verified through analytical and Monte-Carlo simulation studies.