The compensation of polarization mode dispersion (PMD) at high bit-rate is a challenging problem for modern telecom applications. In this connection, the actual problem is to drastically decrease the response time of the polarization modulators. Up to now, for this purpose, several technologies were proposed, that is, electrooptical crystals (e.g. lithium neobate), acousto-optical modulators, nematic and ferroelectric liquid crystals. The latter one is considered as the most perspective due to it fast response time, sensitivity to the electric field polarity and continuous gray scale capability. In this work we present the results of our computer simulations of the performance of the modulator with in-plane electrodes based on deformed helix ferroelectric liquid crystal. Using FEMLAB software package the spatial distribution of electric field was investigated as function of the geometrical parameters of the cell and number of driving electrodes. Using the obtained electrical field distribution, the spatial distribution of optical retardation and the angular orientation of the fast axis were calculated. It was demonstrated that the area with the nearly flat retardation distribution can be reached when the number of electrodes are more than 6 and the distance between them is around 50 micrometers. The obtained results can/will be used for development optimal endless compensator of PMD.