Nyquist filters with robust performance against timing jitter

Abstract

We propose a novel technique for designing finite impulse response (FIR) equiripple Nyquist filters with almost no intersymbol interference (ISI), good robustness to timing jitter, and satisfactory stopband performance. The main step in this technique is the design of an auxiliary Nyquist filter, which has good robustness to timing jitter, using a novel windowing method. The transition band of the equiripple filter is then shaped according to that of this auxiliary filter. The resulting filter takes advantage of the minimax principle for obtaining satisfactory stopband performance and the windowing method for obtaining good robustness to timing jitter. Notable features of the proposed technique are simplicity and flexibility. Examples show superior performance compared with the truncated raised cosine pulse as well as other existing techniques.