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

The Korean Institute of Commucations and Information Sciences (한국통신학회)
권호 표지

Co-Channel Interference Cancellation in Cellular OFDM Networks PART II: Co-Channel Interference Cancellation in Single Frequency OFDM Networks using Soft Decision MLE CCI Canceler

  • Published : 2007.07.31
Download PDF
⟨ Previous Next ⟩

Abstract

In this paper, a new scheme of downlink co-channel interference (CCI) cancellation in OFDM cellular networks is introduced for users at the cell-edge. Coordinated symbol transmission between base stations (BS) is operated where the same symbol is transmitted from different BS on different sub-carriers. At the mobile station (MS) receiver, we introduce a soft decision maximum likelihood CCI canceler and a modified maximum ratio combining (M-MRC) to obtain an estimate of the transmitted symbols. Weights used in the combining method are derived from the channels coefficients between the cooperated BSs and the MS. Simulations show that the proposed scheme works well under frequency-selective channels and frequency non-selective channels. A gain of 9 dB and 6 dB in SIR is obtained under multipath fading and flat-fading channels, respectively.

본 논문에서는 OFDM 셀룰라 네트워크에서 셀 가장자리에 위치한 사용자를 위한 다운링크 동일채널간섭(CCI) 제거 기법을 소개한다. 기지국간의 협력적 심볼 전송은 동일 심볼을 다른 기지국에서 상이한 부반송파를 사용하여 전송함으로서 이루어진다. 단말기에서는 전송된 심볼을 추정하기 위하여 연판정 최대우도 동일채널간섭 제거기(soft decision maximum likelihood CCI canceler)와 수정된 최대비 합성법 (modified maximum ratio combining (M-MRC))을 적용하며, 합성법에 사용된 가중치는 협력 기지국과 단말기 사이의 채널 상수에 의해서 유도된다. 시뮬레이션 결과로부터 제안된 기법이 주파수 선택적 페이딩 채널과 주파수 비선택적 페이딩 채널에서 각기 9 dB와 6dB의 SIR 이득을 보임을 알 수 있다.

Keywords

References

  1. J. G. Andrews, 'Interference cancellation for cellular systems: a contemporary overview,' IEEE Wireless Commun. Magazine, vol. 12, pp. 19-29, Apr. 2005 https://doi.org/10.1109/MWC.2005.1421925
  2. L. Ping, L. Liu, K. Wu, and W. K. Leung, 'Interleave-division multiple-access,' IEEE Trans. on Wireless Communications, vol. 5, no. 4, pp.938-947, Apr. 2006 https://doi.org/10.1109/TWC.2006.1618943
  3. K. I. Lee, K. S. Woo, Y. H. Ko, J. Y. Ahn, and Y. S. Cho, 'An inter-cell interference cancellation method for OFDM cellular systems using a subcarrier-based virtual MIMO,' To appear in IEEE Veh. Tech. Conf.,2006
  4. A. Paulraj, R. Naber and D. Gore, Introduction to space-time wireless communications, Cambridge University Press, 2003
  5. M. Mohaisen and K.H. Chang, 'Maximumlikelihood co-channel interference cancellation with power control for cellular OFDM networks,' KICS Journal, Vol. 32, No. 5, May-2007
  6. H. Yoshino and A. Czylwik, 'adaptive co-channel interference (CCI) cancellation for OFDM communication systems,' in Proc. Intern. Zurich Seminar on Broadband Commun., Feb 2000, pp.245-250
  7. G. Stuber, Principles of Mobile Communications. Georgia, Atlanta: Kluwer, 2001
  8. IEEE Std. 802.16-2004, 'IEEE Standard for Local and metropolitan area networks,' 2004