Browse > Article
http://dx.doi.org/10.5515/KJKIEES.2011.22.4.423

Optimal Soft Decision for Cooperative Spectrum Sensing in Cognitive Radio Systems  

Lee, So-Young (Spectrum & Standardization Research Team, Korea Radio Promotion Association)
Kim, Jin-Young (Department of Wireless Communications Engineering, Kwangwoon University)
Publication Information
The Journal of Korean Institute of Electromagnetic Engineering and Science / v.22, no.4, 2011 , pp. 423-429 More about this Journal
Abstract
Cooperative spectrum sensing is proposed to overcome some problem such as multipath fading and shadowing and to improve spectrum sensing performance. There are different combining methods for cooperative spectrum sensing: hard decision method and soft decision method. In this paper, we analysis the performance of cooperative spectrum sensing with distance based weight that is kind of a soft decision rule for cognitive radio(CR) systems and CR systems sense the spectrum of the licensed user by using a energy detection method. Threshold is determined in accordance with the constant false alarm rate(CFAR) algorithm for energy detection. The signal of licensed user is OFDM signal and the wireless channel between a licensed user and CR systems is modeled as Gaussian channel. From the simulation results, the cooperative spectrum sensing with distance based weight combining(DWC) and equal gain combing(EGC) methods shows higher spectrum sensing performance than single spectrum sensing does. And the detection probability performance with the DWC is higher than that with the EGC.
Keywords
Cognitive Radio(CR); Cooperative Spectrum Sensing; Energy Detection; Equal Gain Combining(EGC); Distance Based Weight Combining(DWC);
Citations & Related Records
연도 인용수 순위
  • Reference
1 FCC, "Facilitating opportunities for flexible, efficient and reliable spectrum use employing cognitive radio technologies", Notice of Proposed Rule Making, ET Docket, no. 03-332, Dec. 2003.
2 FCC, "Spectrum policy task force", Rep. ET Docket, no. 02-135, Nov. 2002.
3 J. Y. Kim, Cognitive Radio Communications, Gyobo Publishers, Seoul, Korea, 2008.
4 J. Mitola III, G. Q. Maguire Jr., "Cognitive radio: making software radios more personal", IEEE Personal Commun., vol. 6, no. 4, pp. 13-18, Aug. 1999.   DOI
5 I. F. Akyildiz, W. Y. Lee, M. Vuran, and S. Mohanty, "Next generation/dynamic spectrum access/cognitive radio wireless networks: a survey", Computer Networks, vol. 50, no. 13, pp. 2127-2159, May 2006.   DOI
6 Z. Quan, S. Cui, and A. H. Sayed, "An optimal strategy for cooperative spectrum sensing in cognitive radio networks", in Proc. of IEEE GLOBECOM 2007, pp. 2947-2951, Nov. 2007.
7 G. Ganesan, Y. Li, "Cooperative spectrum sensing in cognitive radio networks", in Proc. of IEEE DySPAN 2005, pp. 137-143, Nov. 2005.
8 A. Ghasemi, E. S. Sousa, "Asymptotic performance of collaborative spectrum sensing under correlated log-normal shadowing", IEEE Commun. Lett., vol 11, no. 1, pp. 34-36, Jan. 2007.   DOI
9 F. F. Digham, M. -S. Alouini, and M. K. Simon, "On the energy detection of unknown signals over fading channels", in Proc. IEEE Int. Conf. Commun., vol. 5, pp. 3575-579, May 2003.
10 G. Minkler, J. Minkler, CFAR, Magellan Book Company, 1990.