Resource Allocation for OFDMA Systems with Selective Relaying and Energy Harvesting

In this paper, we develop joint resource allocation algorithm for selective user cooperation based OFDMA systems with energy harvesting technology. When relaying is beneficial for the network, mobile users with good channel conditions and low traffic demands can play the role of relays. The mobile user equipments are capable of energy harvesting using "wireless power transfer" technology and only the harvested energy is used for cooperation. The joint optimization problem of power and subcarrier allocation and relay selection is a mixed integer nonlinear program, which is very difficult to solve in general. We propose a novel scheme to solve the problem optimally with polynomial time complexity using dual decomposition approach. Numerical results demonstrate the effectiveness of the proposed scheme in terms of energy efficiency compared to the other existing models in the literature.