DOI QR코드

DOI QR Code

적응 모듈러스와 적응 스텝 크기를 적용한 Hybrid-SMMA 등화 알고리즘의 성능 평가

Performance Evaluation of Hybrid-SMMA Equalization Algorithm based on Adaptive Modulus and Adaptive Stepsize

  • 임승각 (공주대학교 정보통신공학부)
  • Lim, Seung-Gag (Dept. of Information and Communication, Kongju National University)
  • 투고 : 2017.06.21
  • 심사 : 2017.08.11
  • 발행 : 2017.08.31

초록

본 논문은 SMMA (Sliced Multi Modulus Algorithm) 등화 알고리즘에서 등화기의 출력 전력에 비례하는 adaptive modulus와 adaptive stepsize를 적용하므로서 등화 성능을 개선할 수 있는 Hybrid-SMMA 알고리즘에 관한 것이다. 기존 SMMA 알고리즘에서는 등화기의 탭 계수 갱신을 위한 오차 신호를 발생할 때 송신측 신호의 통계 특성치인 modulus를 고정적으로 사용하지만, 제안 Hybrid-SMMA에서는 등화기 출력 신호의 전력에 비례토록 modulus와 오차 신호의 비선형성을 이용하여 stepsize를 적응적으로 변화시킨다. 제안 알고리즘의 개선된 등화 성능을 컴퓨터 시뮬레이션을 통해 확인하였으며, 시뮬레이션 결과 제안 방식이 기존 SMMA보다 모든 성능에서 우월함을 확인하였다.

This paper relates with the Hybrid-SMMA adaptive equalization algorithm that is possible to improve the equalization performance based on adaptive modulus and adaptive stepsize which is propotional to the output power of equalizer in the current SMMA (Sliced Multi Modulus Algorithm). The fixed statistic modulus of transmitted signal is used in current SMMA algorithm in order to generate the error signal for updating the tap coefficient of equalizer. The proposed Hybrid-SMMA based on the adaptive modulus which is propotion to the equalizer output signal power and adaptive stepsize which is fuction of the nonlinearties of error signal. The computer simulation was performed in order to confirm the improved equalization performance of proposed algorithm. As a result of computer simulation, the proposed Hybrid-SMMA has fairly good in every performance than the current SMMA.

키워드

참고문헌

  1. A.Ozen, I.Kaya, B.Soysal, "Variable Step-Size Constant Modulus Algorithm Employing Fuzzy Logic Controller", Wireless Pers. Commun. 54, pp.237-249, 2010. https://doi.org/10.1007/s11277-009-9723-2
  2. S.Abrar, R.A.Axford, "Sliced Multi-modulus Blind Equalization Algorithm", ETRI Jorunal, Vol.27, No.3, pp.257-266, June 2005. https://doi.org/10.4218/etrij.05.0104.0027
  3. S.A.Sheikh, P.Fan, "Two efficient adaptively varying modulus blind equalizers : AVMA and DM/AVMA", Digital Signal Processing 16, pp.832-845, 2006. DOI: 10.1109/INMIC.2005.334416
  4. M.A.Demir, A.Ozen, "A Novel Variable Step Size Adjustment Method Based on Autocorrelation of Error Signal for the Constant Modulus Blind Equalization Algorithm", Radio Engineering, Vol.21, No.1, pp.37-45, April 2012. DOI: 10.1109/SIU.2010.5653136
  5. Z.Liyi, C.Lei, S.Yunshan, "Variable Step-size CMA Blind Equalization based on Non-linear Function of Error Signal", Int. Conf. on Comm. and Mobile Computing, pp.396-399, 2009. DOI: 10.1109/CMC.2009.77
  6. R.Hamzehyan, R.Dianat, N.C.Shirazi, "New Variable Step-Size Blind Equalization Based on Modified Constant Modulus Algorithm", Int. Jour. of Machine Learning and Computing, Vol.2, No.1, pp.30-34, Feb. 2012.
  7. S.G.Lim, "Performance Comparison of S-MMA Adap-tive Equalization Algorithm by Slice Weighting Value in 16-QAM Signal", Jour. of I.W.I.T., Vol.13, No.3, pp.55-61, June. 2013.