Stable Subchannel Allocation for OFDMA Femtocells with Switched Multi-beam Directional Antennas

In this paper, we propose a low-complexity distributed stable subchannel allocation algorithm combined with a low-cost reconfigurable switched multi-beam directional antenna to improve the capacity and the fairness performance for the orthogonal frequency-division multiple access (OFDMA)-based femtocell systems. With the proposed deferred acceptance algorithm, the stable subchannel allocation scheme can achieve a better tradeoff between capacity and fairness. Numerical results show that the proposed stable subchannel allocation scheme with the switched multi-beam antenna can significantly improve femtocell capacity compared to the traditional user-oriented subchannel allocation scheme and ensure the fairness as compared to the traditional channel-oriented subchannel allocation scheme.