Performance Analysis of CDF-Based Relay Selection in Dual-Hop Wireless Networks

In this paper, we propose the proactive and the reactive cumulative distribution function (cdf)-based relay selection schemes with a control parameter (CP) in a dual-hop wireless network to easily control the fairness among relays such as the probability of selecting each relay and achieve full diversity. We analyze the probability of selecting a relay and the average fairness among relays for the proposed schemes. The upper bound of outage probability is derived in closed form for the proactive cdf-based relay selection (CRS) scheme. Exact outage probability is derived in closed form for the reactive CRS scheme. Moreover, we derive the asymptotic outage probabilities at a high-signal-to-noise-ratio region. Numerical results show that the analytical results of the proposed CRS schemes match the simulation results well. It is shown that both the proactive and reactive CRS schemes achieve the same diversity as the channel-gain-based relay selection (CGRS) scheme, which is outage optimal. It is shown that when all CPs are equally set for all relays, the proposed CRS schemes guarantee strict fairness among relays. It is shown that when CPs are set based on the channel condition, the outage probability of the proposed CRS schemes is close to that of the CGRS scheme.