A cross-layer architecture for motion-adaptive video transmission over MIMO channels

In this paper, we study the impact of spatio-temporal variations of a video sequence on wireless MIMO video transmission. In the light of our findings, we propose a cross-layer MIMO video communication architecture for efficient multimedia communication. Existing methods complement Spatial Multiplexing (SM) and Space Time Block Coding (STBC) with enhanced source and channel coding strategies to improve video PSNR at a MIMO receiver. However, these methods ignore the adverse impacts of spatio-temporal content variations on video quality and decoding complexity. We show that the decision to switch between SM and STBC for effective video communication must be based on both channel conditions and motion intensity of a video. We quantify a video's spatio-temporal characteristics using a motion intensity measure, and propose a simple motion-adaptive MIMO video communication technique which can judiciously switch between SM and STBC configurations. Experimental evaluations show that the proposed technique provides significantly better video quality while having very low decoding complexity at the receiver. Based on this technique, we propose a novel cross-layer motion-adaptive architecture for wireless video communication.