A Decentralized Subchannel Allocation Scheme with Inter-Cell Interference Coordination (ICIC) for Multi-Cell OFDMA Systems

Abstract

Inter-cell interference (ICI) is responsible for user throughput degradation and especially for users found near cell border which additionally experience serious path-losses. Efficient methods for ICI mitigation are ICI coordination (ICIC) schemes which allocate certain resources among users in different cells. In this paper we propose a decentralized ICIC scheme in order to mitigate the ICI and enhance the capacity of the users found near the cell-edge area of a wireless multi-cell OFDMA system. Key features of the proposed scheme are the subchannel the allocation in a user selective manner considering instantaneous channel conditions and subchannel reuse minimization. The multi-cell subchannel allocation problem is decomposed into a distributed single-cell optimization problem with inter-cell coordination facilitaded by interfaces similar to X2 in 3GPP Long Term Evolution (LTE) networks. We prove through simulation that the proposed scheme yields better performance than existing conventional schemes.