  Fast radio bursts (FRBs) are extragalactic radio transients with millisecond
duration and extremely high brightness temperature. Very recently, some highly
circularly polarized bursts were found in a repeater, FRB 20201124A. The
significant circular polarization might be produced by coherent curvature
radiation by bunches with the line of sight (LOS) deviating from the bunch
central trajectories. In this work, we carry out simulations to study the
statistical properties of burst polarization within the framework of coherent
curvature radiation by charged bunches in the neutron star magnetosphere for
repeating FRBs. The flux is almost constant within the opening angle of the
bunch. However, when the LOS derivates from the bunch opening angle, the larger
the derivation, the larger the circular polarization but the lower the flux. We
investigate the statistical distribution of circular polarization and flux of
radio bursts from an FRB repeater, and find that most of the bursts with high
circular polarization have a relatively low flux. Besides, we find that most of
the depolarization degrees of bursts have a small variation in a wide frequency
band. Furthermore, we simulate the polarization angle (PA) evolution and find
that most bursts show a flat PA evolution within the burst phases, and some
bursts present a swing of PA.
