QoS-guaranteed joint resource allocation for high-speed moving relay with constrainted backhaul link in OFDMA system

With the flourish of urban public transportation, a larger amount of users request for high quality service in vehicle environments. Moving relay (MR) is proposed as a solution for enhancing the vehicular users experience. But in high-speed environment, serious Doppler spreading impairs the link quality of MR and Macro Base Stations (MBSs), which will cause inter-carrier interference (ICI) in orthogonal frequency division multiplexing access (OFDMA) systems. In this paper, we aim to minimize the total power consumption of MRs two links based on the quality of service (QoS) guarantee for each user, while the backhaul link is constrainted by ICI effect. A joint resource allocation problem including subcarrier and power allocation is studied. We propose an effective method integrating evolutionary genetic algorithm (GA) and Lagrange dual method to find near optimal solution. The near optimal subcarrier allocation is achieved by the GA algorithm. The transmission power minimization problem is tackled by Lagrange dual method and gradient descent method. Simulation results validate the effectiveness of the proposed scheme compared with related works.