  Radio observations of solar flares often reveal various periodic or
quasi-periodic oscillations. Most likely, these oscillations are caused by
magnetohydrodynamic (MHD) oscillations of flaring loops which modulate the
emission. Interpretation of the observations requires comparing them with
simulations. We simulate the gyrosynchrotron radio emission from a
semi-circular (toroidal-shaped) magnetic loop containing sausage-mode MHD
oscillations. The aim is to detect the observable signatures specific to the
considered MHD mode and to study their dependence on the various source
parameters. The MHD waves are simulated using a linear three-dimensional model
of a magnetized plasma cylinder; both standing and propagating waves are
considered. The curved loop is formed by replicating the MHD solutions along
the plasma cylinder and bending the cylinder; this model allows us to study the
effect of varying the viewing angle along the loop. The radio emission is
simulated using a three-dimensional model and its spatial and temporal
variations are analyzed. We consider several loop orientations and different
parameters of the magnetic field, plasma, and energetic electrons in the loop.
In the model with low plasma density, the intensity oscillations at all
frequencies are synchronous (with the exception of a narrow spectral region
below the spectral peak). In the model with high plasma density, the emission
at low frequencies (where the Razin effect is important) oscillates in
anti-phase with the emissions at higher frequencies. The oscillations at high
and low frequencies are more pronounced in different parts of the loop
(depending on the loop orientation). The layers where the line-of-sight
component of the magnetic field changes sign can produce additional
peculiarities in the oscillation patterns.
