  We use 1+1/2 dimensional particle-in-cell plasma simulations to study the
interaction of a relativistic, strongly magnetized wind with an ambient medium.
Such an interaction is a plausible mechanism which leads to generation of
cosmological gamma-ray bursts. We confirm the idea of Meszaros and Rees (1992)
that an essential part (about 20%) of the energy that is lost by the wind in
the process of its deceleration may be transferred to high-energy electrons and
then to high-frequency (X-ray and gamma-ray) emission. We show that in the wind
frame the spectrum of electrons which are accelerated at the wind front and
move ahead of the front is nearly a two-dimensional relativistic Maxwellian
with a relativistic temperature $T=6*10^9\Gamma_T$ K, where
$\Gamma_T=200\Gamma_0$ with the accuracy of ~20%, and $\Gamma_0$ is the Lorentz
factor of the wind, $\Gamma_0>100$ for winds outflowing from cosmological
gamma-ray bursters. Our simulations point to an existence of a high-energy tail
of accelerated electrons with a Lorentz factor of more than $700\Gamma_0$.
Large-amplitude electromagnetic waves are generated by the oscillating currents
at the wind front. The mean field of these waves ahead of the wind front is an
order of magnitude less than the magnetic field of the wind. High-energy
electrons which are accelerated at the wind front and injected into the region
ahead of the front generate synchro-Compton radiation in the fields of
large-amplitude electromagnetic waves. This radiation closely resembles
synchrotron radiation and can reproduce the non-thermal radiation of gamma-ray
bursts observed in the Ginga and BATSE ranges (from a few keV to a few MeV).
