An Improved Frequency-domain Multimodulus Blind Equalization Agorithm under α Noise
Zhe Tang · Research and Exploration in Laboratory · 2015
When constant modulus algorithm is used to equalize multimodulus signals,there are some defects of the slow convergence rate and big steady mean square error,and its performance degenerates in α-stable distribution noise. In order to overcome these disadvantages,an improved frequency-domain multimodulus blind equalization algorithm is proposed. In the proposed algorithm,modulus transform,fast Fourier transform and overlap-save law are combined into blind equalization algorithm based on fractional lower order statistics,fractional lower order statistics is used to restrainα-stable distribution noise,according to the feature of multimodulus signal constellations,modulus transform changes the multimodulus of multimodulus signal to single modulus,the multimodulus signal is equalized effectively. The algorithm's computational loads is greatly reduced by using fast Fourier transform and overlap-save law,orthogonal wavelet transform is used to reduce the autocorrelation of the equalizer input signals. The theoretical analyses and the computer simulations in satellite channels indicate that the proposed algorithm can obtain fast convergence rate and the small steady mean square error. So the proposed algorithm has important reference value for the satellite communications.