Copyright © 2008 The Institute of Electronics, Information and Communication Engineers
Special Section on Cognitive Radio and Spectrum Sharing Technology -- Papers -- Spectrum Sensing |
Study on Soft Decision Based Cooperative Sensing for Cognitive Radio Networks
1 The authors are with the Graduate School of Engineering, Tokyo University of Agriculture and Technology, Koganei-shi, 184-8588 Japan. E-mail: cornelius{at}suzuki-lab.tuat.ac.jp, 2 The author is with the Advanced Wireless Communication research Center (AWCC), The University of Electro-Communications, Chofu-shi, 182-8585 Japan., 3 The author is with the Graduate School of Engineering, Division of Electrical and Computer Engineering, Yokohama National University, Yokohama-shi, 240-8501 Japan., 4 The author is with the Graduate School of Engineering, Tokyo Institute of Technology, Tokyo, 152-8550 Japan.
In this paper, we propose a soft decision based cooperative sensing method for cognitive radio (CR) networks for opportunistic frequency usage. To identify unused frequency, CR should exploit sensing technique to detect presence or absence of primary user and use this information to opportunistically provide communication among secondary users while performance of primary user should not be deteriorated by the secondary users. Because of multipath fading or shadowing, the detection of primary users may be significantly difficult. For this problem, cooperative sensing (CS), where gathered observations obtained by multiple secondary users is utilized to achieve higher performance of detection, has been investigated. We design a soft decision based CS analytically and analyze the detector in several situations, i.e., signal model where single-carrier case and multi-carrier case are assumed and two scenarios; in the first scenario, SNR values of secondary users are totally equal and in the second scenario, a certain SNR difference between secondary users is assumed. We present numerical results as follows. The first scenario shows that there is little difference between the signal models in terms of detection performance. The second scenario shows that CS is superior to non-cooperative sensing. In addition, we presents that detection performance of soft decision based CS outperform detection performance of hard decision based CS.
Key Words: cognitive radio, cooperative sensing, energy detection, cognitive MIMO mesh network
Manuscript received May 11, 2007. Manuscript revised July 20, 2007.
Reference
[1] http://www.ieee802.org/22/ [2] FCC, "Notice of proposed rule making: Unlicensed operation in the TV broadcast bands," ET Docket no.04–186, May 2004. [3] H. Urkowitz, "Energy detection of unknown deterministic signals," Proc. IEEE, vol.55, no.4, pp.523–531, April 1967. [4] S.M. Mishra, A. Sahai, and R.W. Brodersen, "Cooperative sensing among cognitive radios," IEEE ICC, 2006. [5] E. Visotsky, S. Kuffner, and R. Peteron, "On collaborative detection of TV transmissions in support of dynamic spectrum sharing," Proc. DySPAN, pp.338–345, Nov. 2005. [6] K. Po and J. Takada, "Signal detection for analog and digital TV signals for cognitive radio," IEICE Technical Report, SR2006-54, Nov. 2006. [7] A. Ghasemi and E.S. Sousa, "Collaborative spectrum sensing for opportunistic access in fading environments," Proc. DySPAN, pp.131–136, Nov. 2005. [8] K. Sakaguchi, T. Fujii, F. Ono, and K. Umebayashi, "Cognitive MIMO mesh network — Spatial spectrum sharing by using MIMO algorithm," IEICE Technical Report, SR2006-43, Nov. 2006. [9] T. Fujii, K. Umebayashi, F. Ono, and K. Sakaguchi, "Interference avoidance method against primary systems for cognitive radio mesh networks using power limitation," IEICE Technical Report, SR2006-44, Nov. 2006. [10] F. Ono and K. Sakaguchi, "Throughput performance of wireless mesh network using multiple anntenas," IEICE Technical Report, SN2006-46, Dec. 2006. [11] K. Umebayashi, T. Fujii, F. Ono, K. Sakaguchi, and Y. Suzuki, "Cognitive MIMO mesh network — Study on energy based signal detection in cognitive radio," IEICE Technical Report, RCS2007, Jan. 2007. [12] S.M. Kay, Fundamentals of Statistical Signal Processing, vol.2, Detection Theory, Prentice-Hall Signal Processing Series, 1998.
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