Improved Nyquist filter with piece-wise linear transfer characteristic

Abstract

This paper investigates a family of improved Nyquist filters derived from a modified piece-wise rectangular frequency characteristic. They produce a family of ISI-free pulses with an asymptotic decay rate of t−2 that shows comparable or better ISI performance with regard to some recently proposed pulses. The frequency characteristic is composed of twelve linear segments, each defined by two points. The coordinate of the points are selected in order for the filter to result in a minimum value of the probability of error when sampled with a small time offset. The results are comparable or outperform the polynomial pulse [4] taken as a reference.