Outage probability of cooperative diversity systems with opportunistic relaying based on decode-and-forward transmission

Opportunistic relaying with cooperative diversity has been introduced in [1] as a simple alternative protocol to the distributed space-time coded protocol while achieving the same diversity-multiplexing tradeoff performance as a point-to-point multiple-input multiple-output scheme. In this paper, we derive an upper and lower bound on the per hop output signal-to-noise ratio cumulative distribution function, probability density function and moment generating function. We also derive approximate but tight closed-form expressions for the lower and upper bounds of the outage probability of opportunistic relaying based on decode-and-forward transmission under the assumption of unbalanced/balanced hops and independent, identical distributed Rayleigh fading channels.