Advanced Graph-Coloring Spectrum Allocation Algorithm for Cognitive Radio

Cognitive radio can use the hole of licensed spectrum efficiently without interference to the primary users through sensing the wireless environment dynamically. An improved algorithm of spectrum allocation based on graph-coloring theory is proposed in this paper. It can significantly reduce the cost of allocating channels through parallel allocation thus enhance the extent of reusing channels but causing no interference between cognitive users. Simulation proves that the cost of this algorithm is only slightly greater than the parallel algorithm while its system reward is obviously higher than that of former algorithms. As a result it will further optimize the spectrum allocation and boost the spectrum utilization.