Adaptive partial frequency reuse in LTE-Advanced relay networks

With the employment of relay nodes (RNs) in Long Term Evolution Advanced (LTE-Advanced) networks, some cell-edge User Equipments (UEs) are served by RNs to improve received signal strength and mitigate interference. In in-band mode, they are allowed to reuse the resources allocated to the UEs connected to the evolved Nodes B (eNBs) in the same cell. Frequency reuse inside a cell can increase the number of available resources per cell and can also produce intra-cell interference. In order to alleviate the detrimental impact of interference and maximise network performance at the same time, we propose an adaptive partial frequency reuse (APFR) scheme, which includes a resource partitioning algorithm and a route selection algorithm. We first formulate the APFR problem into a generalised proportional fairness problem. After getting a mathematical solution, we determine the number of reused resources, and then the resource partitioning and route selection algorithms are derived sequentially. Simulation results show that the proposed APFR scheme can achieved both larger throughput and better fairness than the benchmarking algorithms with different RN transmitting power and various RN positions.