Interference Analysis and Subchannel Allocation Schemes in Tri-Sectored OFDMA Systems

This paper analyzes the interference aspects of tri-sectored OFDMA systems and evaluates the performance of some subchannel allocation schemes to mitigate inter-sector interference. To maximize spectral efficiency, it is preferred to adopt frequency reuse of 1. But, carrier to interference and noise ratio (CINR) values at the boundary of sectors are extremely deteriorated. Two subchannel allocation methods are compared and evaluated in this environment. One is to maximize disparity, which is to maximize the number of subchannels in good CINR values, and the other is to minimize disparity, which is to maximize the number of subchannels in moderate CINR values. These schemes are compared under proportionally fair scheduling algorithm. Simulation results regarding to throughput show that the schemes outperform random allocation schemes in 802.16 based systems.