Improved Nyquist filter with a convex-convex piecewise-parabolic transfer function

This paper presents and investigates a novel approach for constructing a family of ISI-free pulses that shows comparable or better ISI performance in the presence of sampling errors, as compared with some recently proposed pulses. The transfer characteristic of the filter is composed of parabolic pieces. The coordinates of the junction points are determined in order to produce a minimal value of the error probability when the impulse response is sampled with a fixed time offset that accounts for the imperfect synchronization in the receiver. The results outperform those of poly filter, which so far was the best one.