A novel cognitive radio spectrum assignment scheme for maximizing system utilization

Abstract

This paper deals with the problem of spectrum sharing among primary and secondary users in a cognitive radio. To use the spectrum efficiently and flexibly, the cognitive radio spectrum allocation problem was formulated as a graph coloring problem (GCP). However, GCP is known to be a nondeterministic polynomial-time (NP)-hard and cannot be solved for the practical system. Inspired by the efficiency of the cross-entropy (CE) method for finding near-optimal solutions in huge search spaces, this paper proposes the application of the CE method to allocate cognitive radio spectrum to achieve nearoptimal spectrum utilization. Simulation results show that the average reward values obtained using the proposed CE method are better than those obtained using the conventional method. Keywords: cross-entropy method, cognitive radio, spectrum allocation Classification: Science and engineering for electronics References[1] W. Zhang, J. Yang, Q. Yan, and L. Zhang, "Optimal multiband spectrum sensing in cognitive radio," IEICE Electron. Express, vol. 7, no. 20, pp. 1557-1563, Oct. 2010 , vol. 11, no. 4, pp. 555-576, May 2006. [5] Z. Zhao, Z. Peng, S. Zheng, and J. Shang, "Cognitive radio spectrum allocation using evolutionary algorithms," IEEE Trans. Wireless Commun., vol. 8, no. 9, pp. 4421-4425, Sept. 2009. [6] C. Liao, J. Chen, Y. Tang, and S. Li, "Parallel algorithm of spectrum allocation in cognitive radio," J. Electron. Inf. Technol., vol. 29, no. 7, pp. 1608-1611, July 2007