Partial Frequency Allocation in Downlink OFDMA Based on Evolutionary Algorithms

This paper describes the optimization of the frequency allocation in the downlink of an Orthogonal Frequency Division Multiple Access (OFDMA) cellular network by means of centralized adaptive frequency management. The adaptive frequency allocation is performed off-line based on a Genetic Algorithm (GA) which computes for each cell an optimal number of radio resource blocks as guided by the geometry and the interference induced from adjacent cells. The objective of the optimization algorithm is to reduce interference and improve cell edge user throughput while preserving overall system throughput performance. For certain scenarios simulation results demonstrate gains up to 20% for the cell-edge user throughput as compared to a partial frequency 3-reuse scheme.