一种跨层自适应无线视频传输方法

An adaptive cross-layer scheme for end-to-end video transmission on wireless channels

针对实时视频传输对吞吐率、丢包率、时延等服务质量的要求，对无线信道下视频端到端传输的失真进行分析，提出了一种跨层自适应方法，在层间传递信息来协调各层的工作过程，对物理层、链路层和应用层联合优化设计，适应无线信道的变化。获得信源失真和信道失真之间的平衡，使总失真最小．仿真结果证明。在一般信道信噪比的情况下，该方法较之单独使用白适应调制编码或者自动请求重传。在视频恢复质量上得到改善，峰值信噪比提高了0．8～1．0dB．

The throughput, packet loss and delay requirements of real-time video transmission were considered. The distortion of end-to-end video transmission on wireless channels was analyzed. An adaptive cross-layer scheme was proposed to design the physical layer, the link one and the application one wholly and optimistically and to adapt to the changes of wireless channels. The simulation results showed that in comparison with the AMC（adaptive modulation and coding） or ARQ（automatic repeat request） schemes, this scheme has improved significantly the visual performance. The overall peak signal to noise ratio for end-to-end video transmission was gained by 0.8 - 1.0 dB in this adaptive scheme.