We aim to present a comparative study of the performances, in terms of the mean PSNR (peak signal-to-noise ratio), of a UMTS/TDD transmission system for H.263 compressed and turbo-coded video sequences. Several parameters are varied, among them: the rate of occurrence of intra coded frames; the video compression level; the bit error rate of the transmission channel. We also present a methodology for determining the best scheme for repartition of the global channel bandwidth between source and channel coding, in order to minimize the global distortion on the transmitted sequences.