Introducing PHY-layer fairness in amplify and forward cooperative diversity systems

We introduce the concept of fairness at the physical-layer in amplify and forward cooperative diversity systems, which reflects the need for equally allocating the consumed power among the relays. To this end, we propose a relay-selection method, which utilizes knowledge on both the instantaneous and average channel conditions in order to encompass this concept. We also provide a closed-form expression for the outage probability in the high signal to noise ratio (SNR) regime. Numerical results show that the outage performance of the proposed scheme resembles closely the performance of the "best relay selection" scheme, albeit maintaining the average power consumptions equal.