Title :
LSF-CMA Equalization Algorithm for OFDM System using Zero-Padding Technique
Author :
Alayyan, Faisal O. ; Leung, Yee Hong ; Zoubir, Abdelhak M.
Author_Institution :
Etisalat Univ. Coll., Sharjah, United Arab Emirates
Abstract :
We introduce an adaptive channel equalization algorithm for orthogonal frequency division multiplexing (OFDM) employing high bandwidth-efficiency quadratic amplitude modulation (QAM) signaling. Our approach uses the guard band to yield a unique equalizer estimate through a least square fitting (LSF) criterion. To refine the equalizer estimation, a combination of a LSF and constant modulus algorithm (CMA) based equalizer is proposed. In order to minimize the error of the overall structure, a stochastic gradient algorithm is implemented. It is shown that the proposed scheme is superior and more robust in low signal to noise ratio (SNR) environments. Simulation results demonstrate that using the combination scheme improves adaptive channel equalization by increasing convergence rate and decreasing the steady-state mean square error.
Keywords :
OFDM modulation; adaptive equalisers; least squares approximations; mean square error methods; quadrature amplitude modulation; LSF-CMA equalization; OFDM system; adaptive channel equalization; constant modulus algorithm; least square fitting; orthogonal frequency division multiplexing; quadratic amplitude modulation; steady-state mean square error; stochastic gradient algorithm; zero-padding technique; Adaptive equalizers; Amplitude modulation; Convergence; Least squares approximation; Noise robustness; OFDM; Quadrature amplitude modulation; Signal to noise ratio; Stochastic resonance; Yield estimation; Adaptive blind equalization algorithm; CMA; GI-restoral property; MCMA; OFDM;
Conference_Titel :
Signal Processing and Communications, 2007. ICSPC 2007. IEEE International Conference on
Conference_Location :
Dubai
Print_ISBN :
978-1-4244-1235-8
Electronic_ISBN :
978-1-4244-1236-5
DOI :
10.1109/ICSPC.2007.4728609
