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

The Korean Institute of Commucations and Information Sciences (한국통신학회)
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A Study on Channel Equalization for Asynchronous DS-CDMA Systems

비동기 DS-CDMA 시스템에서 채널 등화에 관한 연구

  • 민장기 (광운대학교 전자통신공학과 신호처리 연구실)
  • Published : 2000.10.01
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Abstract

Blind Equalization Method without training sequences is proposed for channel efficiency in mobile communication system for asynchronous multi-user DS-CDMA. the risk of mis-convergence of weak-power users is increased because of small regions of convergence in case of near-far effect in CMA(Constant Modulus Algorithm) which is the simplest has high performance and widely implemented. In despite the problem a equalization using Newton method has higher performance than a conventional method in squared error and eye-pattern.

비동기 DS-CDMA 다중 사용자 환경의 이동통신 시스템에서 채널의 효율을 높이기 위해 학습 신호열을 사용하지 않는 블라인드 등화 기법을 제안한다. 블라인드 등화 기법 중에서 가장 단순하면서 성능이 좋고 구현하기 쉬운 CMA(Constant Modulus Algorithm)는 근거리-원거리 효과(near-far effect)가 심하게 나타날 경우 전력이 약한 사용자들의 수렴 영역이 작아져 mis-convergence 위험성이 증가한다. 이런 경우에도 Newton 방식을 이용한 등화 기법은 자승 오차와 Eye-Pattern의 성능 비교를 통해 기존의 방법 보다 우수함을 확인할 수 있었다.

Keywords

References

  1. Digital Communications J.Proakis
  2. 한국통신학회 논문지 v.24 비동기 DS-CDMA 시스템에서의 블라인드 다중사용자 채널 추정 기법 정형성;성하종;이충용;윤대희
  3. IEEE Trans. Comm. v.COM-23 A Method of Self-Recovering Equalization for Multilevel Amplitude Modulation System Y.Sato
  4. IEEE Trans. Comm. v.COM-28 Self-Recovering Equalization and Carrier Tracking in Two-Dimensional Data Communication System D.N.Godard
  5. IEEE Trans. ASSP. v.31 no.2 A New Approach to Multipath Correction of Constant Modulus Signals J.R.Treichler;B.G.Agee
  6. IEEE ICASS'90 Blind Equalization Based on Radius Directed Apaptation Michael J. Ready;Richard P. Gooch
  7. IEEE Proceeding A Normalized Constant-Modulus Algorithm Douglas L. Jones
  8. IEEE Signal Proc, Letters v.5 no.1 Normalized Adaptive Decion Directed Equalization A. Lee Swindlehurst
  9. Proc. of the 36th Allerton Conference on Communication, Control, and Computing Minimum-Entropy Blind Acquisition /Equalization for Uplink DS-CDMA P.Schniter;C.R.Jhonson,Jr.
  10. Adaptive Filter Theory(2nd Ed.) S.Haykin
  11. Proceedings of the IEEE v.86 no.10 Blind Equalization Using the Constant Modulus Criterion: A Review C.R.Jhonson,Jr.(et al.)
  12. Proc. Asilomar Conf. On Signals, Systems, and Computers Characterization of The Regions of Convergence of CMA Adaptive Blind Fractionally Spaced Equalizers W.Chung;C.R.Jhonson,Jr.
  13. Adaptive Signal Processing Widrow;Bernard
  14. presented at the 8th IEEE DSP Workshop Fast Algorithm for Blind Adaptive Equalizers G.Yan;H.Fan