DFT-based coordination mechanism for inter-cell interference mitigation in wireless OFDM systems

Abstract

One of the most serious impairments when deploying wireless Orthogonal Frequency Division Multiplexing (OFDM) networks with frequency-reuse one is cell-edge performance. Standard interference coordination approaches, like enhanced Inter-Cell Interference Coordination (eICIC) and Coordinated Multi-Point (CoMP), can improve performance at the cell-edge, but improvements are only significant when ideal or almost ideal backhaul is considered. Moreover, interferences from uncoordinated cells and from cells belonging to other clusters are not properly considered in the standards. This paper proposes an alternative Discrete Fourier Transform (DFT)-based clustered coordination technique for the downlink, wherein intra-cluster interference is effectively rejected, and interferences from other clusters and uncoordinated cells are reduced by a factor equal to the cluster size. The proposed coordination technique does not require costly exchange of user plane data among the cells involved, therefore being applicable in non-ideal backhaul scenarios. Simulations show significant performance improvements in low signal to noise and interference conditions.