Combined Partial Reuse and Soft Handover in OFDMA Downlink Transmission

The inter-cell interference problem is a key issue in a multi-cell OFDMA system. A number of inter-cell interference mitigation schemes have been suggested to address this problem and among them, partial reuse is considered a most promising one for emerging OFDMA systems. In this paper, we propose an inter-cell interference mitigation scheme for an OFDMA downlink system. The proposed scheme makes use of a combination of partial reuse and soft handover. The basic idea of the proposed scheme is to select the better signal quality among a partial reuse scheme and a soft handover scheme for the cell edge users. Compared to the conventional partial reuse scheme, simulation results show that the cell edge throughput can be significantly improved by using the proposed scheme. Furthermore, considering the data-rate fairness among the users, the results prove that our approach can give better average cell throughput as compared with the conventional partial reuse scheme, especially for a very fair system.