  In our previous paper [Phys. Rev. E 95, 062122 (2017)] we considered the
optical channel modelled by the nonlinear Schr\"odinger equation with zero
dispersion and additive Gaussian noise. We found per-sample channel capacity
rof this model. In the present paper we extend per-sample model by introducing
the initial signal dependence on time and the output signal detection
procedure. The proposed model is a closer approximation of the realistic
communication link than the per-sample model where there is no dependence of
the initial signal on time. For the proposed model we found the correlators of
the output signal both analytically and numerically. Using these correlators we
built the conditional probability density function. Then we calculated an
entropy of the output signal, a conditional entropy, and the mutual
information. Maximizing the mutual information we found the optimal input
signal distribution, channel capacity? and their dependence on the shape or the
initial signal in the time domain for the intermediate power range.
