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Performance Analysis of NM-MMA Adaptive Equalization Algorithm in Nonconstant Modulus Signal

Nonconstant Modulus 신호에서 NM-MMA 적응 등화 알고리즘의 성능 해석

  • Lim, Seung Gag (Dept. of Information and Communication, Kongju National University)
  • 임승각 (공주대학교 정보통신공학부)
  • Received : 2016.12.19
  • Accepted : 2017.04.07
  • Published : 2017.04.30

Abstract

This paper propose the NM-MMA (Novel Mixed-MMA) that is possible to improving the convergence speed of current MMA algorithm and reducing the high MSE of SE-MMA algorithm, and its equalization performance were analyzed. The cost function of the NM-MMA configured as the sum of appropriate weights of gradient vector of current MMA and SE-MMA, and then it used for the updating the tap coefficient of equalizer. The computer simulation was performed applying the same environment in the channel, step size and signal to noise ratio, and the same performance index in equalizer output signal constellation, residual isi, MSE, SER was used. As a result of computer simulation, the proposed NM-MMA has fast convergence time than MMA, and less in MSE and SER performance compared to SE-MMA.

본 논문에서는 nonconstant modulus 신호에서 기존 MMA 알고리즘의 수렴 속도를 개선하고 SE-MMA 알고리즘의 높은 MSE를 줄일 수 있는 NM-MMA (Novel Mixed-Multi Modulus Algorithm) 알고리즘을 제안하며, 이의 등화 성능을 해석하였다. NM-MMA에서는 비용 함수로서 기존 MMA와 SE-MMA 비용 함수의 gradient vector 를 적절한 가중치의 합으로 구성하여 탭 계수 갱신에 이용하므로서 수렴 속도와 MSE 성능을 개선할 수 있다. 이를 위하여 동일한 채널과 스텝 크기 및 신호대 잡음비를 적용하여 컴퓨터 시뮬레이션을 수행하였으며 성능 해석을 위한 지수로는 등화기 출력 성상도, 잔류 isi, MSE와 SER을 적용하였다. 컴퓨터 시뮬레이션의 결과 제안 NM-MMA는 기존 MMA의 수렴 속도를 개선하고, SE-MMA보다 적은 MSE 성능과 SER 성능을 얻을 수 있음을 확인하였다.

Keywords

References

  1. J. Yang, J.J. Werner and G.A.Dumont, "The multi-modulus blind equalization algorithm", 13th Int. conf. of DSP, Vol. 1, pp.127-140, 2-4 July, 1997. DOI : https//doi.org/10.1109/TCOMM.2005.855017
  2. Wen si-yuan, Liu Feng, "A Computationally Efficient Multi-modulus Blind Equalization Algorithm", 2nd IEEE Int. conf. of Infor. Eng. and Management, pp.685-687, 2010. DOI : https//doi.org/10.1109/ICIME.2010.5478261
  3. V. Weerackody, S.A. Kassam, K.R. Laker, "A simple hard-limited adaptive algorithm for blind equalization", IEEE Trans. on Circuits and System, Vol.39, No.7, pp.482-487, July 1992. DOI : https//doi.org/10.1109/82.160173
  4. S.A.Sheikh, P.Fan, "A New Multimodulus Blind Equalizer for Dense QAM Constellation", Wireless, Mobile and Network, Int. Conf. of ICWMMN2006, pp.1-4, 2006.
  5. Yecai Guo, Juwei Zhao, "A Novel Mixed Constant Modulus Blind Equalization Algorithm", 7th Int. conf. of ICSP'04, pp.319-322, 2004.
  6. S.G. Lim, D.S. Kang, "Performance of SE-MMA Blind Equalization Algorithm in QAM System", Jour. of I.I.B.C., Vol.13, No.3, pp.63-69, June 2013.
  7. G. Im, C. Park, H. Won, "A Blind Eualization with the Sign Algorithm for Broadband Access", IEEE Com. Letter, Vol.5, No.2, pp.70-72, Feb. 2001. https://doi.org/10.1109/4234.905939