A decision-directed blind equalization with the error variance estimation

A blind equalization algorithm may be switched to a decision-directed (DD) scheme in order to speed up the convergence rate. In this paper, we propose a new blind equalization scheme that automatically switches to the DD mode. The proposed scheme operates in two mode: blind equalization mode and a DD mode. The mode is determined by the region in which the equalizer output lies, and the region varies as a function of the estimate value of the error variance. Only the equalized signal that falls in the region of confidence is used to calculate the variance. From simulation results, it is shown that this scheme can achieve faster convergence and small MSE.