Spectrum assignment in infrastructure based cognitive radio networks

Spectrum assignment is an important research problem in cognitive radio networks. Different from the conventional spectrum assignment algorithms which are mainly designed for ad hoc networks, in this paper, a new spectrum assignment algorithm for infrastructure based cognitive radio networks is proposed. This algorithm aims at maximizing the average bandwidth per flow, and avoiding the spectrum waste by idle secondary basestations. We have performed packet-level simulation studies to compare the performance of our proposed algorithm with two graph-coloring based algorithms. The simulation results show that our algorithm can dramatically improve network throughput, decrease the average packet delay, and average packet drop ratio.