Performance of selection DF scheme for a relay system with non-identical Rician fading

In this paper, we investigate the performance of a generic relay system for small cells. The main features include the selection decode-and-forward (DF) scheme, Rician and Rayleigh fading, single or repeated transmissions in direct link, and maximal-ratio combining at destination. We are able to derive a set of closed-form expressions for the end-to-end performance. Based on these formulas, we define a metric, called the differential outage probability (DOP), to characterize the differential performance due to repetition coding. It is shown that the benefit of repetition diminishes quickly when the components of line-of-sight (LOS) increase.