Analysis of new variable step-size NLMS-based algorithm for OFDM systems

Main Article Content

Suchada Sitjongsataporn


New variable step-size normalised least mean square (NLMS) algorithm is proposed for frequency domain equalisation in the orthogonal frequency division multiplexing (OFDM) systems. An optimal variable step-size approach is introduced how to derive with the method of mean square deviation scheme based on NLMS algorithm. An adaptive frequency domain equalisation approach based on the variable step-size NLMS algorithm is presented with regard to the proposed optimal variable step-size algorithm for OFDM-based systems. We present simulation results to compare the proposed algorithm on the basis of their performance and rate of convergence. Simulation results show that the bit error rate as well as the mean square error can be reduced by the proposed algorithm. The proposed algorithm can be achieved in terms of fast convergence and robustness in comparison with the existing algorithm.

Article Details

Research Articles


Y.Lin, S.Phoong and P.P.Vaidyanathan, Filter Bank Transceivers for OFDM and DMT systems, Cambridge University Press, 2011.

T.I.Haweel, and P.M.Clarkson, “A Class of Order Statistic LMS Algorithms”, IEEE Transactions on Signal Processing, vol. 40, no. 1, pp. 44-53, Jan. 1992.

J.A.Chambers, Normalization of Order Statistics LMS Adaptive Filters Sequential Parameter Estimation, Schlumberger Cambridge Research, U.K., 1993.

S.Sitjongsataporn and P.Yuvapoositanon, “Adaptive Step-size Order Statistic LMS-based Time-domain Equalisation in Discrete Multitone Systems”, Discrete Time Systems, Mario Alberto Jord´an (Ed.), ISBN: 978-953-307-200-5, InTech, April 2011.

H.Shin, A.H.Sayed and W.Song, “Variable Step-Size NLMS and Affine Projection Algorithms”, IEEE Signal Processing Letters, vol. 11, no. 2, pp. 132-135, Feb. 2004.

P.S.R.Diniz, Adaptive Filtering Algorithms and Practical Implementation, Springer, 2008.

3rd Generation Partnership Project, 3GPP TS 25.101 - Technical Specification Group Radio Access Network; User Equipment (UE) Radio Transmission and Reception (FDD) (Release 9), June 2010.