Achieving fairness by aggregate power allocation in opportunistic cooperation networks

Within a wireless opportunistic network, one of the lucky users gets an opportunity to utilize the whole radio resource. However some of the unlucky users keep silent during an unexpected period resulting from severe wireless environment and imperfect scheduling algorithms. An opportunistic cooperation protocol is proposed that can achieve equivalent performance measured in terms of outage probability, in which scheme the opportunistic user helps to relay what need retransmitting indicated by the destination and selects the appropriate power allocation to pursue fairness. The proposed scheme deploys superposition coding and successive interference cancellation at relay and destination, respectively. To improve the spectral efficiency, the modified cooperation architecture involves two opportunistic users which work in turn. The simulation results demonstrate that the protocol obtains better performance compared with the conventional methods.