A Universal Frequency Reuse System in a Mobile Cellular Environment

We propose a universal frequency reuse (UFR) system that can reuse effectively a given frequency resource in a mobile cellular environment. The key concept is to control mutual interferences among neighboring cells in a systematic manner. The system first assigns the whole frequency resource to all cells, so that the whole resource could be reused without any restrictions in all the cells as in the cellular systems with frequency reuse factor of 1. Then, it defines a cell-specific resource allocation rule for each cell, so as to control mutual interferences among neighboring cells in a cooperative way. In our case, the resource allocation rules are designed so that they can avoid maximally inter-cell interference (ICI) when the loading factor is less than a threshold loading factor, while exceeding the threshold, ICI would be averaged over the whole frequency resource. Hence, the proposed system can maintain ICI always at the minimum level, in turn expecting greater spectrum reuse efficiency. Finally, we perform extensive computer simulations in order to verify the effectiveness of the proposed reuse system, assuming an OFDMA-based cellular system. From simulation results, we show that the UFR system provides quite better spectrum reuse efficiency, regardless of omni-cell and 3-sector cell systems.