A Novel Frequency Reuse Scheme for Multi-Cell OFDMA Systems

In this paper, we propose a novel frequency reuse scheme for multi-cell orthogonal frequency division multiplexing access (OFDMA) systems for co-channel interference (CCI) reduction. We divide all the available subcarriers into two groups with one used for the central region of the cell and another for the cell boundary. The frequency reuse factor (FRF) is 1 in the central region and 3 in the boundary. The edge of the cell is partitioned into three sectors. Intra-cell orthogonality is guaranteed in this scheme, so all the subcarriers may use the same transmit power. The subcarriers of the super and regular group can be allocated adaptively and flexibly according to the users´ distribution and service requirements. Which frequency group a user can use is determined according to the distance between the user and the serving BS or the signal to interference plus noise ratio (SINR) of the user. Simulation results show that this scheme can bring higher channel capacity and lower CCI, and can also increase the data rate at the cell edge.