  One possibility to break down the capacity limit in optical transmission
systems are higher spectral efficiencies, enabled by Faster-than-Nyquist
signaling. Here we present the utilization of non-orthogonal time division
multiplexing of sinc pulse sequences for this purpose. The mathematical
expression, with a representation of the Nyquist sinc sequence by a cosine
Fourier series and simulation results show that non-orthogonal time-division
multiplexing increases the transmittable symbol rate by up to 25%.
