Joint power allocation and relay assignment for max-min fairness in cooperative networks

Abstract

Cooperative communication is shown to be a promising technology to enhance the capacity of wireless transmission without additional equipments. Under this communication paradigm, both relay selection and power allocation significantly affect the overall system performance. Thus, this paper studies the joint power allocation and relay assignment problem to optimize the Max-Min fairness of cooperative network. We first analyze the trade-off between the bandwidth provision and power consumption for different communication schemes. According to the analytic results, a heuristic algorithm PRF is designed to determine the fairness factor with the binary searching. The analyses show that PRF algorithm can obtain the approximate ratio 1- ξ, where ξ is an arbitrarily small positive constant. Meanwhile, this paper also presents another heuristic algorithm JFAP, which uses the offer-and-gain mechanism to reach the Max-Min fairness. The simulation results show that PRF and JFAP algorithms can improve the fairness factor at least 36% and 32% compared with the direct transmission scheme in many situations.