Partitioned quadrature amplitude modulation for mobile video transmission

This paper presents a dual priority transmission system for mobile channels suitable for mobile video applications. The transmission system is comprised of a 16 quadrature amplitude modulation (QAM) technique and channel-coding scheme. The twin class 16-QAM system is used to transport a compressed video bitstream, which is partitioned to mach the bit-error sensitivity of the transmitted symbol in terms of mapping in the constellation diagram and picture quality. The partition scheme is based on a separation of the variable-length coded (VLC) discrete cosine transform (DCT) coefficients within each block. This partition scheme is then applied to split the ITU-T H.263-coded video bitstream and is suitable for constant bit rate transmission where the allocation of the VL-coded information amongst the two partitions is performed adoptively. The performance of the twin-class 16-QAM transmission system is evaluated under additive white Gaussian noise (AWGN) conditions. The simulation results show that this strategy results in a higher quality of the reconstructed video data.