Comparison of uniform and non-uniform M-QAM schemes for mobile video applications

This paper introduces a unique set of techniques to support reliable and efficient video transmission over mobile channels. The twin class uniform and nonuniform partitioned M-level Quadrature Amplitude Modulation (QAM) system is used to transport a compressed video bitstream which is partitioned to match the bit-error sensitivity of the transmitted symbol in terms of mapping in the constellation diagram and picture quality. The partitioning scheme is based on a separation of the Variable Length (VL) coded Discrete Cosine Transforms (DCT) coefficients within each block, and is applied to split the ITU-T H.263 coded bitstream. Various scenarios for splitting the bitstream are investigated and their results are compared and analysed thoroughly. The performance of the transmission system is evaluated under Additive White Gaussian Noise (AWGN) conditions. The results show video partitioning forms an effective method for transmitting video information over mobile channels.