Constrained blind equalizer using adaptive nonlinear filter
Ryo Koizumi, Teruyuki Miyajima, Kazuo Yamanaka · Electronics and Communications in Japan (Part III Fundamental Electronic Science) · 2003
Abstract In this paper, a new adaptive equalizer that adjusts the nonlinear filter without training signals is proposed and its performance is evaluated. In the proposed equalizer, the nonlinear filter has constraints, while learning is carried out by means of the output energy minimization algorithm. Since the proposed equalizer has nonlinearity, it has a better bit error rate than the linear equalizer. Further, since no training signal is needed, it is to be expected that the transmission efficiency is superior to that in an equalizer with training signals. In order to evaluate the performance limitations of the proposed equalizer, an optimum equalizer with constrained filter input is derived. By means of simulations, a performance evaluation is carried out and the effectiveness of the proposed equalizer is demonstrated. Further, in order to improve the performance of the proposed equalizer for a linear communication channel, an intersymbol interference canceler and an algorithm for correcting the error are proposed and their effectiveness is demonstrated. © 2003 Wiley Periodicals, Inc. Electron Comm Jpn Pt 3, 87(3): 17–29, 2004; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/ecjc.10145