Optimal resource allocation for time sharing relaying system

A time sharing relaying system model using Orthogonal Frequency Division Multiple Access (OFDMA) is investigated in this paper, where eNode B transmits to relay and macro user equipments (M-UEs) during the first time slot, and in the second time slot messages are conveyed to remote user equipments (R-UEs) by the relay with relay acting in the decode-and-forward (DF) mode. These two transmissions are allocated in the same frequency domain. By converting this system model into a bandwidth sharing one, we formulate and solve an optimization problem to maximum data rate by optimizing the bandwidth allocated to each link. Simulation results show that our proposed optimal resource allocation algorithm outperforms the traditional schemes significantly, especially when the channel condition between relay and R-UE is preferable.