The Journal of the Institute of Internet, Broadcasting and Communication (한국인터넷방송통신학회논문지)

The Institute of Internet, Broadcasting and Communication (한국인터넷방송통신학회)
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A Performance Comparison of CR-MMA and CM-MMA Equalization Algorithm in 2-dimensional QAM System

2차원 QAM 시스템에서 CR-MMA 와 CM-MMA 등화 알고리즘의 성능 비교

  • Lim, Seung-Gag (Dept. of Information and Communication, Kongju National University)
  • 임승각 (공주대학교 정보통신공학부 정보통신공학전공)
  • Received : 2018.06.20
  • Accepted : 2018.08.10
  • Published : 2018.08.31
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Abstract

This paper compares the adaptive eualization performance of CR-MMA (Constellation Reduction-MMA) and CR-MMA (Constellation Matching-MMA) in order to minimization of intersymbol interference that is occur in channel for 2-dimensional QAM signal. For obtain the error signal in order to updating the tap coefficient of conventional adaptive equalization algorithm MMA, the CR-MMA converts the constellation reduction concept of high order 2-dimensional QAM nonconstant modulus signal to constant modulus signal and the CM-MMA use the constellation matchine error concept in order to force the matching the $2^{nd}$ and $4^{th}$ cumulant of equalizer output and transmitted signal constellation. By applying the different method for getting the error signal, these algorithm are possible to obtain the improved equalization performance compared to the conventional MMA algorithm, the improved performance of CR-MMA and CM-MMA were compared by computer simulation in this paper. As a result of simulation, the CM-MMA has more better performance in the equalizer internal performance than CR-MMA, but not in equalizer external performance as in SER.

본 논문에서는 2차원 QAM 시스템에서 전송시 채널에서 발생되는 부호간 간섭을 최소화하기 위한 적응 등화 알고리즘인 CR-MMA와 CM-MMA의 등화 성능을 비교하였다. 기존 적응 등화 알고리즘 MMA의 탭 계수 갱신을 위한 오차 신호를 얻을 때 CR-MMA는 nonconstant modulus 특성을 갖는 고차 2차원 QAM 신호를 constant modulus 신호로 변환하는 constellation reduction 개념을 이용하며, CM-MMA는 등화기 출력과 송신 신호점의 2차와 4차 cumulant를 강제로 일치시키기 위한 constellation matching error 개념을 이용한다. 서로 상이한 오차 신호를 얻는 과정을 거쳐 이들은 기존 방식보다 개선된 등화 성능을 얻을 수 있게 되므로, 논문에서는 이들을 컴퓨터 시뮬레이션을 통해 등화 성능을 비교하였다. 컴퓨터 시뮬레이션 결과 등화기 내부의 성능에서는 CM-MMA가 CR-MMA보다 우월하였지만, 외부 성능에서는 CR-MMA가 CM-MMA보다 우월함을 확인하였다.

Keywords

References

  1. Lin He, M. G. Amin, C. R. Jr, R. C. M alkemes, "A Hybrid Adaptive Blind Equalization Algorithm for QAM Signals in Wireless Communications", Vol. 52, No. 7, pp. 2058-2069, July 2004. DOI : 10.1109/TSP.2004.828913
  2. J. Yang, J. J. Weren, G. A. Dumont, "The Multi-modulus Blind Equalization Algorithm", 13th Int. Conf. D.S.P. Processing, pp. 127-130, 1997. DOI : 10.1109/ICDSP.1997.627988
  3. J. T. Yuan, K. D. Tsai, "Analysis of the Multi-modulus Blind Equalization Algorithm in QAM communication Systems", IEEE Trans. on Comm., Vol. 53, No. 9, pp.1427-1431, Sept. 2005. DOI : 10.1109/TCOM.2005.855017
  4. W. Rao, "Amplitude Transformation-Based Blind Equalization Part 2 : Suitable for High-Order QAM Signal", Procedia Environmental Sciences 10, pp. 1282-1286, 2011. https://doi.org/10.1016/j.proenv.2011.09.205
  5. Lin He, S. A. Kassam, "Convergence Analysis of Blind Equalization Algorithm using Constellation-Matching", IEEE Trans. on Com., Vol. 56, No. 11, pp.1765-1768, Nov. 2008. DOI : 10.1109/TCOM.2008.060370
  6. S. G. Lim, "Performance Improvement of MMA Adaptive Equalization Algorithm by using the Constellation Reduction in QAM Signal", Jour. on I.I.B.C., Vol.14, No.5, pp.103-109, Sep. 2014.
  7. S. G. Lim, "The Performance Comparison of CR-CMA and CM-CMA Adaptive Equalization in 16-QAM Signal", Jour. on I.W.I.T., Vol. 11, No. 3, pp.115-120, June 2011.