一种改进的H.264/AVC空时编码方案及仿真实现

传统H.264无线视频传输系统误码率较高并且重建图像质量差,针对此问题提出一种改进方案。传输系统采用H.264编码器和多输入多输出(MIMO:Multiple-input Multiple-output)系统级联的模型:基于不等差错保护思想,在信源端依照优先级顺序将H.264码流分为两部分,利用空时预编码技术的分集优势提升高优先级码流的传输可靠性,同时不改变低优先级码流的误码率,提高了无线传输系统整体性能。仿真结果表明:与传统方案相比,改进方案可以在不提高总发送功率的前提下获得较好的重建图像质量,在低信噪比时,重建图像的平均峰值信噪比可提升近7dB,且检测复杂度适中。

An Improved H.264/AVC Transmission Scheme Based on Space-Time Block Coding System

A new scheme for H.264/AVC video transmission based on MIMO was proposed,which could achieve a higher coding gain instead of increasing total transmission power and frequency usage compared to the traditional two antennas STBC system.H.264 coded information was divided into two parts according to their different importance;each part was transmitted differently over MIMO system.The unequal error protection scheme is that the more important part was transmitted based on pre-coding technique over STBC system to improve the error resilience.The error rate of the unimportant one was similar to the traditional video transmission method.Simulation results show that the new scheme has demonstrated significant improvements,especially when the channel is in bad condition.It yields improvements in average PSNR of up to 7 dB compared to the traditional scheme.