  The preparation of science objectives of the ESA's PLATO space mission will
require the implementation of hare-and-hound exercises relying on the massive
generation of representative simulated light-curves. We developed a light-curve
simulator named the PLATO Solar-like Light-curve Simulator (PSLS) in order to
generate light-curves representative of typical PLATO targets, i.e. showing
simultaneously solar-like oscillations, stellar granulation, and magnetic
activity. At the same time, PSLS also aims at mimicking in a realistic way the
random noise and the systematic errors representative of the PLATO
multi-telescope concept. To quantify the instrumental systematic errors, we
performed a series of simulations at pixel level that include various relevant
sources of perturbations expected for PLATO. From the simulated pixels, we
extract the photometry as planned on-board. The simulated light-curves are then
corrected for instrumental effects using the instrument Point Spread Functions
reconstructed on the basis of a microscanning technique that will be operated
during the in-flight calibration phases. These corrected light-curves are then
fitted by a parametric model, which we incorporated in PSLS. We show that the
instrumental systematic errors dominate the signal only at frequencies below
20muHz and are found to mainly depend on stellar magnitude and on the detector
charge transfer inefficiency. To illustrate how realistic our simulator is, we
compared its predictions with observations made by Kepler on three typical
targets and found a good qualitative agreement with the observations. PSLS
reproduces the main properties of expected PLATO light-curves. Its speed of
execution and its inclusion of relevant stellar signals as well as sources of
noises representative of the PLATO cameras make it an indispensable tool for
the scientific preparation of the PLATO mission.
