SIR based Adaptive Subchannel Allocation in OFDMA Cellular System

This paper introduces a novel SIR based resource allocation algorithm with the aim of avoiding joint resource allocation at a single central point in a cellular system and consequent decision delays in the network Each base station controller assigns channel resources to each user in such a way that the ratio of signal to energy leaked in to neighboring cells in maximized. The system simulator employs hexagonal cell structure and Okumura-Hata path loss model. The proposed algorithm is compared with the conventional resource allocation algorithms and gives considerable performance gains at varying cell loads. In addition, the proposed algorithm improves the spectral efficiency while keeping the system fair resulting in consequent multifold improvement in outage performance. Finally, to show the effect of decision delays inherent in resource allocation problem, the performance of these algorithms is also investigated as a function of channel update time.