Study On The Adaptive Polynomial Equalizer

In the increasingly developing circumstance with high data rate, the communication channel's nonlinearity has become the main factor affecting the bit error rate, when only the nonlinear equalization technology with based on nonlinear filter theory can remove the ISI effectively. So, the research on the nonlinear channel equalization is now a hot spot in the high-rated wireless communication area.This paper is performed mainly on the adaptive equalization technology in the nonlinear channel, based on summarizing the present study on nonlinear adaptive signal processing and nonlinear channel equalization domestically and abroad. By using polynomial adaptive filtering and neural network technology, novel ways on how nonlinear adaptive filter (or neural network) can be applied into the nonlinear equalization are discussed and several novel nonlinear equalizers are proposed, which have shown better equalization performance than the general ones.The main results of this paper are as follows:1. Based on DCT polynomial adaptive equalizer is proposed for autocorrect matrix's characteristic condition of input's signals and product coupling items, which has a very simple structure and few parameter but with good nonlinear equalization performance.2. Linear Filer linked Nonlinear polynomial adaptive equalizer, Neural Network linked Nolinear polynomial adaptive equalizer , Neural Network Legendre polynomial adaptive equalizer and Neural Network Chebyshev polynomial decision feedback equalizer for nonlinear polynomial adaptive filers are proposed, the equalizer's anti-nonlinear performance can be improved effectively.3. Linear Filters linked Nonlinear and Neural Network linked Nonlinear polynomial complex adaptive equalizers are proposed for complex nonlinear channel, the complex algorithm is given,. Simulation's results show that they can effectively compensate the phase and amplitude loss in the complex channel.