  We use numerical modeling to study the features of parametric
(quasi-Cherenkov) cooperative radiation arising when an electron bunch passes
through a crystal (natural or artificial) under the conditions of dynamical
diffraction of electromagnetic waves in the presence of shot noise. It is shown
that in both Laue and Bragg diffraction cases, parametric radiation consists of
two strong pulses: one emitted at small angles with respect to the particle
velocity direction and the other emitted at large angles to it. Under Bragg
diffraction conditions, the intensity of parametric radiation emitted at small
angles to the particle velocity direction reaches saturation at sufficiently
smaller number of particles than the intensity of parametric radiation emitted
at large angles. Under Laue diffraction conditions, every pulse contains two
strong peaks, which are associated with the emission of electromagnetic waves
at the front and back ends of the bunch. The presence of noise causes a chaotic
signal in the interval between the two peaks.
