A novel prioritized spatial multiplexing for MIMO wireless system with application to H.264 SVC video

Spatial multiplexing MIMO wireless system is an excellent choice for next generation broadband multimedia communications because of its parallel transmission capability. A major challenge for such MIMO system is that it usually requires appropriate decomposition of both wireless channels and multimedia data bitstreams. Existing approaches to MIMO channel decomposition have been passively based on simple channel feedback. To facilitate proper match between decomposed channels with compressed video that exhibit variable priority for different layer of bitstreams, it is necessary to proactively prioritize the decomposed MIMO channels. We present in this paper a novel pre-coding scheme capable of integrating both channel and source characteristics in order to achieve the desired prioritized spatial multiplexing. This pre-coding scheme is applied to the transmission of video data compressed with H.264 Scalable Video Coding (SVC) standard. Based on the desired bit-error-rate (BER) and signal-to-noise-ratio (SNR) for each SVC video layer, the base layer video is proactively assigned the highest priority sub-channel to guarantee minimum required quality while enhancement layers are mapped to other lower priority sub-channels. Comparing with existing schemes, the proposed pre-coder has low computational complexity and is suitable for rapid hardware implementation. The experimental results demonstrate that the proposed prioritized spatial multiplexing approach can efficiently enhance the quality of SVC video streaming over MIMO systems.