On the relationship between chromatic dispersion and transmitter filter response in duobinary optical communication systems

It is shown through numerical simulation that limiting the spectral occupancy of a duobinary optical signal, which can be achieved by an appropriate choice of electrical transmitter filter response, is necessary in order to receive a benefit from duobinary transmission in single-mode optical communication systems. It is explained why such band limiting gives an improvement in dispersion immunity, and why ideal duobinary signaling is ineffective. The results are in good agreement with published experimental work.