The Journal of Korean Institute of Electromagnetic Engineering and Science (한국전자파학회논문지)

The Korean Institute of Electromagnetic Engineering and Science (한국전자파학회)
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Performance of Cognitive Radio Systems Based on Multiple Orthogonal Sequences

다중 직교 시퀀스를 이용한 인지 무선 시스템의 성능

  • Lee, Kyung-Sun (Department of Wireless Communications Engineering, Kwangwoon University) ;
  • Kim, Yoon-Hyun (Department of Wireless Communications Engineering, Kwangwoon University) ;
  • Kim, Jin-Young (Department of Wireless Communications Engineering, Kwangwoon University)
  • Received : 2011.12.02
  • Accepted : 2012.07.31
  • Published : 2012.08.31
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Abstract

Ad hoc networks can be used under difficult conditions, where it is difficult to construct infrastructures, such as shadowing areas, disaster areas, war area, and so on. In order to support to considerable and various wireless services, more spectrum resources are needed. However, efficient utilization of the frequency resource is difficult because of spectrum scarcity and the conventional frequency regulation. Ad-hoc networks employing cognitive radio(CR) system that guarantee high spectrum utilization provide effective way to increase the network capacity. However, there is a problem that all CR user do not fairly use the primary user's idle bandwidth which has been sensed. In this paper, to solve this problem, we propose the spectrum sharing algorithm which uses the multiple orthogonal sequences based on the code division multiple access(CDMA). From the proposed algorithm, it is expected that system performance of CR based ad-hoc network is improved significantly and it can be applied to the implementation of CR based ad-hoc network system.

Ad-hoc 네트워크는 음영지역, 재난지역, 전쟁 시와 같은 통신 인프라가 구축되기 어려운 상황에서 유용하게 사용될 수 있다. 그러나 음성 및 데이터 서비스 등과 같은 무선 서비스의 제공을 위해 많은 양의 네트워크 용량이 필요하게 되지만, 기존의 제한된 주파수 자원에 따른 주파수 부족 상황 및 주파수 자원 정책의 규제에 따라 원활한 주파수 사용이 어려운 상황이다. 이에 따라 높은 주파수 활용을 제공하는 인지 무선 시스템을 ad-hoc 네트워크에 적용하여 보다 다양하고 확장된 네트워크 서비스를 제공할 수 있다. 하지만 인지 무선 시스템을 통해 센싱한 1차 사용자의 유휴 대역을 모든 CR 사용자들이 공평하게 사용할 수 없다는 문제점이 있다. 이러한 문제점을 해결하고자 본 논문에서는 CDMA 방식의 다중 orthogonal sequence를 이용하여, 하나의 주파수 대역 내에서도 여러 명의 CR user가 간섭 없이 효율적인 주파수 대역을 활용할 수 있는 기법을 제안하였으며, 이를 통해 인지 무선 시스템에서의 성능 향상을 보여 준다.

Keywords

References

  1. J. Y. Kim, Cognitive Radio Systems, Gyobo Publishers, Seoul, Korea, 2008.
  2. S. Haykin, "Cognitive radio: Brain-empowered wireless communications", IEEE J. Select. Areas Commun., vol. 23, no. 2, pp. 201-219, Feb. 2005. https://doi.org/10.1109/JSAC.2004.839380
  3. 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. https://doi.org/10.1109/98.788210
  4. I. F. Akyildiz, W. Y. Lee, M. C. Vuran, and S. Mohanty, "Next generation dymamic spectrum access cognitive radio wireless networks: a survey", Computer Networks, vol. 50, pp. 2127- 2159, Sep. 2006. https://doi.org/10.1016/j.comnet.2006.05.001
  5. D. Cabric, S. M. Mishra, and R. W. Brodersen, "Implementation issues in spectrum sensing for congnitive radios", 38th Annual Asilomar Conference on Signals, Systems and Computers, Nov. 2004.
  6. C. K. Toh, Ad Hoc Mobile Wireless Networks: Protocolsand Systems, Prentice Hall PTR, 2002.
  7. Charles E. Perkins, Ad Hoc Networking, Addison- Wesley, 2001.
  8. R. C. Dixon, Spread Spectrum Systems, John Willey & Sons, 1976.
  9. H. H. Chen, H. W. Chiu, "Generation of perfect orthogonal complementary codes for their applications in interference-free CDMA systems", in Proc. PIMRC, vol. 1, pp. 734-738, Sep. 2004.
  10. S. J. Xu, D. B. Li, "Ternary complementary orthogonal sequences with zero correlation window", in Proc. PIMRC, vol. 2, pp. 1669-1672,Sep. 2003.
  11. H. Donelan, T. O' Farrell, "Method for generating sets of orthogonal sequences", Electron. Lett., vol. 35, no. 18, pp. 1537-1538, Sep. 1999. https://doi.org/10.1049/el:19991046
  12. Bin Wang, Dongmei Zhao, "Performance analysis in CDMA-based cognitive wireless networks with spectrum underlay", IEEE Globecom Proceedings, pp. 1-6, 2008.
  13. Kanke Gao, S. N. Batalama, D. A., Pados, and J. D. Matyjas, "Cognitive CDMA channelization", Signals, Systems and Computers, 2009 Conference Record of the Forty-Third Asilomar Conference on, pp. 672-676, Nov. 2009.
  14. S. Ghavami, B. Abolhassani, "Opportunistic communications in multi-rate CDMA systems for cell capacity improvement using cognitive radio", International Symposium on Telecommunications(IST 2008), Tehran, Iran, pp. 193-198, Aug. 2008.
  15. Hsiao-hwa Chen, Jun-Feng, and Naoki Suehiro, "A multicarrier CDMA architecture based on orthogonal complementary codes for new generations of wideband wireless communications", IEEE Communications Magazine, Oct. 2001.