New Dynamic Resource Utilization Technique Based on Fractional Frequency Reuse

Worldwide interoperability for microwave access (WiMAX) base stations (BS) use the fractional frequency reuse (FFR) technique to control inter-cell interference in cellular networks. One of the challenges in FFR is the unused radio resource in the downlink (DL) sub-frame. This paper proposes a dynamic resource utilization approach to eliminate the resource wastage typical of the conventional FFR technique. The proposed approach not only enhances the radio resource utilization of the BS efficiently, but also takes into account the variations in the population density. We deal with the partial usage of sub-channel mode in the DL sub-frame of the WiMAX BS based on orthogonal frequency division multiplexing access. A new FFR data rate formula is derived based on theoretical analysis. Quantitative measurements demonstrate that the dynamic model gives optimal results, enhancing the conventional FFR in terms of a variety of metrics. The data rate, subcarrier efficiency, and spectral efficiency are increased by 2.176 Mbps, 0.14 bit/subcarrier/burst, and 0.218 bps/Hz, respectively. In addition, in the new approach, the DL sub-frame is fully utilized (100 %), the number of served users is increased by 28.57 %, and the number of utilized slots is increased by 34.48 %. The effective utilization of resources and bandwidth characteristic of this approach makes it a strong candidate for BS deployment in cellular networks where the user density changes constantly.