Distributed power allocation for efficient inter-cell interference management in multi-cell OFDMA systems

Abstract

In this paper, we present a new power allocation algorithm called distributed inter-cell power allocation (DIPA) that improves the throughput-fairness trade-off without inter-BS coordination for multi-cell OFDMA systems in fast time-varying environment. In order to preclude the affection of instantaneous channel variation, the DIPA is designed to operate in large time scale (or super-frame) based on the long-term average channel condition, as opposed to the user scheduling which is done in short time scale (or frame) based on the short-term instantaneous channel condition. In addition, to reflect the channel conditions of the multiple users, the DIPA is designed to determine the power allocation preferred by each user individually by using a simplified version of the water-filling scheme and then incorporate the individual power allocations into one policy. According to computer simulations the DIPA algorithm turns out to improve both the cell throughput and cell-boundary users' throughput, and increase the performance gain in the practical systems having irregular cell configuration.