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Abstract: In cognitive radio systems, the design of spectrum sensing has to face the challenges of radio sensitivity and wide-band frequency agility. It is difficult for a single cognitive user to achieve timely and accurate wide-band spectrum sensing because of hardware limitations. However, cooperation among cognitive users may provide a way to do so. In this paper, we consider such a cooperative wide-band spectrum sensing problem with each of the cognitive users able to imperfectly sense only a small portion of spectrum at a time. The goal is to maximize the average throughput of the cognitive network, given the primary network’s collision probability thresholds in each spectrum sub-band. The solution answers the essential questions: to what extent should each cognitive user cooperate with others and which part of the spectrum should the user choose to sense? An exhaustive search is used to find the optimal solution and a heuristic cooperative sensing algorithm is proposed to simplify the computational complexity. Inspired by this optimization problem, two practical cooperative sensing strategies are then presented for the centralized and distributed cognitive network respectively. Simulation results are given to demonstrate the promising performance of our proposed algorithm and strategies.

[1] Cabric, D., Mishra, S.M., Brodersen, R.W., 2004. Implementation Issues in Spectrum Sensing for Cognitive Radios. Proc. 38th Asilomar Conf. on Signals, Systems and Computers, 1:772-776.

[2] Cabric, D., Tkachenko, A., Brodersen, R., 2006. Spectrum Sensing Measurements of Pilot, Energy, and Collaborative Detection. Proc. IEEE Military Communication Conf., p.1-7.

[3] Chen, Y., Zhao, Q., Swami A., 2008. Joint design and separation principle for opportunistic spectrum access in the presence of sensing errors. IEEE Trans. Inf. Theory, 54(5):2053-2071.

[4] Digham, F.F., Alouini, M.S., Simon, M.K., 2007. On the energy detection of unknown signals over fading channels. IEEE Trans. Commun., 55(1):21-24.

[5] FCC (Federal Communications Commission), 2003. Cognitive Radio Technologies Proceeding. Report ET Docket, No. 03-108.

[6] Ghasemi, A., Sousa, E.S., 2005. Collaborative Spectrum Sensing for Opportunistic Access in Fading Environments. Proc. 1st IEEE Int. Symp. on Dynamic Spectrum Access Networks, p.131-136.

[7] Ghasemi, A., Sousa, E.S., 2007. Asymptotic performance of collaborative spectrum sensing under correlated log-normal shadowing. IEEE Commun. Lett., 11(1):34-36.

[8] Haykin, S., 2005. Cognitive radio: brain-empowered wireless communications. IEEE J. Sel. Areas Commun., 23(2):201-220.

[9] Jia, J., Qian, Q., Shen, X., 2008. HC-MAC: a hardware-constrained cognitive MAC for efficient spectrum management. IEEE J. Sel. Areas Commun., 26(1):106-117.

[10] Lai, L., Gamal, H.E., Jiang, H., Poor, H.V., 2008. Cognitive Medium Access: Exploration, Exploitation and Competition. Available from http://arxiv.org/abs/0710.1385 [Accessed on Aug. 20, 2008].

[11] Liu, X., Shankar, S., 2006. Sensing-based opportunistic channel access. Mob. Netw. Appl., 11(4):577-591.

[12] Mishra, S.M., Sahai, A., Brodersen, R.W., 2006. Cooperative Sensing Among Cognitive Radios. Proc. IEEE Int. Conf. on Communication, 4:1658-1663.

[13] Mitola, J., 2000. Cognitive Radio: An Integrated Agent Architecture for Software Defined Radio. PhD Thesis, Royal Institute of Technology, Stockholm, Sweden, p.15-300.

[14] Mitola, J., Maguire, G.Q., 1999. Cognitive radio: making software radios more personal. IEEE Pers. Commun., 6(4):13-18.

[15] Pawelczak, P., Janssen, G.J., Prasad, R.V., 2006. Performance Measures of Dynamic Spectrum Access Networks. Proc. IEEE Global Telecommunication Conf., p.1-6.

[16] Peh, E., Liang, Y.C., 2007. Optimization for Cooperative Sensing in Cognitive Radio Networks. Proc. IEEE Wireless Communication and Networking Conf., p.27-32.

[17] Su, H., Zhang, X., 2008. Cross-layer based opportunistic MAC protocols for QoS provisionings over cognitive radio wireless networks. IEEE J. Sel. Areas Commun., 26(1):118-129.

[18] van Tree, H.L., 2001. Detection, Estimation, and Modulation Theory: Part I. Wiley-Interscience, New York, USA, p.100-120.

[19] Vapnik, V.N., 2000. The Nature of Statistical Learning Theory (2nd Ed.). Springer, New York, USA, p.125-135.

[20] Varshney, P.K., 1997. Distributed Detection and Data Fusion. Springer, NewYork, USA, p.160-179.

[21] Zhao, Q., Tong, L., Swami, A., Chen, Y., 2007. Decentralized cognitive MAC for opportunistic spectrum access in ad hoc networks: a POMDP framework. IEEE J. Sel. Areas Commun., 25(3):589-600.