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Estimation of Zero-Error Probability of Constant Modulus Errors for Blind Equalization

블라인드 등화를 위한 상수 모듈러스 오차의 영-확률 추정 방법

  • Kim, Namyong (Division of Electronics, Information & Communication Engineering, Kangwon National Unversity)
  • Received : 2014.02.26
  • Accepted : 2014.08.21
  • Published : 2014.10.31

Abstract

Blind algorithms designed to maximize the probability that constant modulus errors become zero carry out some summation operations for a set of constant modulus errors at an iteration time inducing heavy complexity. For the purpose of reducing this computational burden induced from the summation, a new approach to the estimation of the zero-error probability (ZEP) of constant modulus errors (CME) and its gradient is proposed in this paper. The ZEP of CME at the next iteration time is shown to be calculated recursively based on the currently calculated ZEP of CME. It also is shown that the gradient for the weight update of the algorithm can be obtained by differentiating the ZEP of CME estimated recursively. From the simulation results that the proposed estimation method of ZEP-CME and its gradient produces exactly the same estimation results with a significantly reduced computational complexity as the block-processing method does.

상수 모듈러스 오차가 영이 될 확률을 최대화하도록 설계된 블라인드 등화 알고리듬은 한 반복시간에서 합산과정을 수행하여 큰 복잡성을 유발한다. 합산과정에서 생기는 이러한 계산상의 부담을 줄여보고자 상수 모듈러스 오차 (CME)의 영확률(ZEP)과 그것의 기울기를 추정하는 새로운 접근 방법을 이 논문에서 제안하였다. 다음 반복시간에서 CME의 ZEP는 현행 CME의 ZEP를 기반으로 하여 반복적으로 계산될 수 있음을 보였다. 알고리듬의 가중치 계산을 위한 기울기도 반복적 추정 방법에 의해 구해진 CME의 ZEP를 미분하여 구해질 수 있음을 제시하였다. 시뮬레이션에서 기존의 블록 처리에 의해 구하던 방법과 비교하였을 때, 제안한 방법에 의해 구해진 CME의 ZEP와 기울기가 상당히 줄인 계산량에도 불구하고 완전히 동일한 추정 결과를 보였다.

Keywords

References

  1. W. M. Moh, Y. Chen, "Multicasting flow control for hybrid wired/wireless ATM networks," Performance Evaluation, Vol. 40, Mar. 2000, pp. 161-194. https://doi.org/10.1016/S0166-5316(99)00074-7
  2. L. M. Garth, "A dynamic convergence analysis of blind equalization algorithms," IEEE Trans. on Comm., Vol. 49, April. 2001, pp. 624-634 https://doi.org/10.1109/26.917769
  3. F. Mazzenga, "Channel estimation and equalization for M-QAM transmission with a hidden pilot sequence," IEEE Trans. on Broadcasting, Vol. 46, June. 2000, pp. 170-176 https://doi.org/10.1109/11.868934
  4. J. R. Treichler and B. Agee, "A new approach to multipath correction of constant modulus signals," IEEE Trans. Acoust., Speech, Signal Process. Vol. ASSP-31, Nov. 1983, pp. 349-372.
  5. Sedarat and K. Fisher, Multicarrier communication in presence of biased-Gaussian noise sources, Signal Processing, Vol. 88, July 2008, pp. 1627-1635. https://doi.org/10.1016/j.sigpro.2007.11.025
  6. S. Unawong, S. Miyamoto, and N. Morinaga, A novel receiver design for DS-CDMA systems under impulsive radio noise environments, IEICE Trans. Comm., Vol. E82-B, June 1999, pp. 936 -943.
  7. J. Principe, D. Xu and J. Fisher, Information Theoretic Learning in: S. Haykin, Unsupervised Adaptive Filtering, Wiley, (New York, USA), 2000, pp. 265-319.
  8. I. Santamaria, P. P. Pokharel, and J. C. Principe, Generalized correlation function: Definition, properties, and application to blind equalization, IEEE Trans. Signal Processing, Vol.54, June 2006, pp. 2187-2197. https://doi.org/10.1109/TSP.2006.872524
  9. N. Kim, "Performance analysis of maximum zero-error probability algorithm for blind equalization in impulsive noise channels," Journal of Korean Society for Internet Information, vol. 11, Oct. 2010, pp. 1-8.
  10. E. Parzen, "On the estimation of a probability density function and the mode," Ann. Math. Stat. Vol. 33, 1962, p.1065. https://doi.org/10.1214/aoms/1177704472
  11. S. Yassin, H. Tawfik, "Reduced complexity decision feedback channel equalizer using series expansion division", AICT 2013 : The Ninth Advanced International Conference on Telecommunications, Rome, Italy, June 2013, pp. 219-223.
  12. J. Park, Y. Whang, and K. Kim, "Low complexity MMSE-SIC equalizer employing time-domain recursion for OFDM systems", IEEE Signal Processing Letters, Vol. 15, Oct. 2008, pp. 633-636 https://doi.org/10.1109/LSP.2008.2003991
  13. V. Swathi, K. Rajani and K. Padmaja, "Blind equalization based on modified constant modulus algorithm", International Journal of Advanced Research in Computer and Communication Engineering, Vol. 3, Issue 5, May 2014, pp. 6523-6525.
  14. M. Demir and 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, April 2012, pp. 37-45.