The Journal of Korean Institute of Communications and Information Sciences (한국통신학회논문지)

The Korean Institute of Commucations and Information Sciences (한국통신학회)
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Inter-cell DCA Algorithm for Downlink Wireless Communication Systems

하향링크 무선 통신 시스템에서의 Inter-cell DCA 알고리즘

  • 김효수 (강원대학교 전자통신공학과) ;
  • 김동회 (강원대학교 전자통신공학과) ;
  • 박승영 (강원대학교 전자통신공학과)
  • Published : 2008.07.30
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Abstract

In OFDMA (Orthogonal Frequency Division Multiple Access) system that frequency reuse factor is 1, as the same channels in the neighborhood cells creates inter-cell co-channel interference which provides a resource underutilization problem, channel allocation schemes to minimize inter-cell interference have been studied. This paper proposes a new CNIR (Carrier to Noise and Interference Ratio)-based distributed Inter-cell DCA (Dynamic Channel Allocation) algorithm in the OFDMA environment with frequency reuse factor of 1. When a channel allocation is requested, if there is not a free channel in home cell or the available free channels in home cell do not satisfy a required threshold value, the proposed Inter-cell DCA algorithm finds CNIR values of available free channels in the neighborhood cells and then allocates a free channel with maximum CNIR value. Through the simulation results, we find that the proposed scheme decreases both new call block rate and forced termination rate due to new call generation at the same time because it increases channel allocation probability.

주파수 재 사용률이 1인 OFDMA(Orthogonal Frequency Division Multiple Access) 시스템에서는 인접한 셀에서 동일채널을 사용하는 것은 셀 간 간섭(Inter-cell-Interference)이 발생하므로 셀 간 간섭을 최소로 하는 채널할당이 이루어져야 한다. 본 논문에서는 OFDMA환경에서 새로운 최대 CNIR(Carrier to Noise and Interference Ratio) 기반의 분산형 Inter-cell DCA (Dynamic Channel Allocation) 알고리즘을 제안한다. 제안된 Inter-cell DCA 알고리즘은 자신의 셀에서 채널할당 요구 시 자신의 셀 내에서 채널이 포화상태이거나 할당 가능한 채널이 남아 있지만 주변 셀 간섭으로 인해 기준 CNIR 문턱치 값을 만족하지 못할 경우에도 인접한 셀의 할당 가능한 채널들의 CNIR을 검색하여 최대 값을 갖는 채널을 할당하는 방법이다. 제안된 방법은 채널 할당 확률을 높여 신규호 블록율과 신규호 생성에 의한 기존채널의 강제 종료율을 동시에 감소시켜 시스템 수율을 향상시킬 수 있음을 시뮬레이션을 통해 확인하였다.

Keywords

References

  1. D. Kivanc, G. Li, and H. Liu, "Computationally efficient bandwidth allocation and power control for OFMDA," IEEE Trans. Wireless Commun., Vol.2, No.6, pp.1150-1158, Nov. 2003 https://doi.org/10.1109/TWC.2003.819016
  2. G. Li and H. Liu "Downlink dynamic resource allocation for multicell OFDMA system," in Proc. IEEE VTC Fall 2003
  3. Z. Wang and R. S-Gallacher, "Frequency reuse scheme for cellular OFDM systems" Electronics Letters, Vol.38, No.8, pp.387-388, Apr. 2002 https://doi.org/10.1049/el:20020255
  4. S. Yoon, Y. Cho, C.-B. Chae, and H. Lee, "System level performance of OFDMA forward link with proportional fair scheduling," in Proc. PIMRC, Vol.2, pp.1384-1388, Sep.2004
  5. N. Lee and S. Bahk, "Dynamic channel allocation using the interference range in multi-cell downlink systems," in Proc. IEEE WCNC, pp.1716-1721, March 2007
  6. E. Oh, M. Cho, S. Han, C. Woo, D. Hong "Performance analysis of dynamic channel allocation based on reuse partitioning in multi-cell OFDMA uplink systems," IEICE Trans. Fundamental, Vol.E89-A, No.6, June 2006
  7. J. Heo, I. Cha, K. Chang, "A novel transmit power allocation algorithm combined with dynamic channel allocation in reuse partitioning - based OFDMA/FDD system," in Proc. IEEE ICC, pp.5654-5659, 2006
  8. I.Katzela and M.naghshineh, "Channel Assignment Schemes for Cellular Mobile Telecommunication Systems : A Comparative Study" IEEE Personal Communications, Vol.3, june 1996, pp.10-31
  9. J. S. Lee and L. E. Miller, CDMA System Engineering Handbook, Cambridge Univ. Press, 1992
  10. D. P. Agrawal and Q. Zeng, Introduction to Wireless and Mobile Systems. University of Cincinnati Press, 2004
  11. E. Gelenbe and G. Pujolle, Introduction to Queuing Networks, New York: John Wiley & Sons,1987
  12. H. Harada and R. Prasad, Simulation and software radio for mobile communications, Artech House Publisher May 2002
  13. 3GPP2 Technical Specification Group C R1002, 1xEV-DV Evaluation Methodology (v13.1), 2003
  14. Recommendation ITU-R M.1225, Guidelines for Evaluation of Radio Transmission Technologies for IMT-2000, 1997
  15. 3GPP TR 25.892 V1.1.0, Feasiblity Study for OFDM for UTRAN Enhancement (Release 6), May 2004