Adjustment of the Position of the Reference Tap of an Adaptive Equalizer

The present structure of adaptive least mean-square error (LMSE) equalizers for data transmission has an unnecessary constraint of a fixed position for the reference tap. This constraint limits their performance. In this paper a gradient-directed method of adjusting the position of the reference tap is developed to minimize the mean-square distortion (MSD). A scheme for implementing this modified equalizer is proposed. Results of computer simulation are shown that indicate that for channels with delay distortion some improvement in performance can be achieved.