Dynamic Frequency Allocation in Fractional Frequency Reused OFDMA Networks

This paper considers the problem of subcarrier scheduling in the downlink of multicell OFDMA networks. It proposes a dynamic fractional frequency reuse cell architecture that partitions subcarriers into two groups. One is reused in the whole cell area whereas the other is partitioned into sectors and used orthogonally. The proposed architecture allows dynamic allocation of users to the group of subcarriers. This dynamic allocation of users is different from the existing architectures where users are partitioned according to fixed thresholds. Next, we propose an efficient hierarchical solution which first allocates subcarriers to the groups and next opportunistically schedules subcarriers to the users. The overall scheme allows frequency reuse factor of 1 with reduced inter-cell interference, increased trunking gain and satisfied minimum data rate requirements. Simulation results illustrate the usefulness of the proposed solution.