A Graceful Wireless Video Delivery Scheme Using Rateless Codes

UEP is one of the most effective technique to improve the quality of video, and rateless codes can adapt to the channel transmission and will decode with smooth and continuous probability, there will be rateless code and UEP technique combined and applied to the wireless video transmission, give full play to the advantages of these two technologies, you can no need to change the traditional video coding structure to achieve a smooth quality video reconstruction. Based on the above ideas, this paper designs a UEP transmission scheme based on unequal distribution of decoding symbols and based on unequal distribution of matrix weights, and the two UEP transmission scheme is tested through simulation platform.This paper analyzes the impact to the video reconstruction quality of the error diffusion caused by I, P, B frames and different macroblock position of the same video frame. Secondly, analyzes the principle of coding and decoding of rateless codes, and combines the basic theory of H.264, discusses the wireless video transmission based on rateless codes can adapt to the channel transmission, eliminate quality level influence and achieve smooth video quality performance. Again, by constructing the video distortion model and rateless codes decoding success probability model, designed the UEP transmission scheme based on unequal distribution of decoding of symbols, the experimental results show that, under the 2048 symbols / RCM Packet, the scheme can get more than EEP transmission scheme for the traditional single sign of the high gain of about 1.7dB, and when the source bandwidth and channel bandwidth equal, this scheme can obtain high gain of about 7dB to the SoftCast which is simulate transmission scheme. Finally, by constructing the optimal UEP matrix, designed the UEP transmission scheme based on unequal distribution of the weight matrix, the experimental results show that, under the same number of encoded symbols, the scheme can be obtained high gain of about 3dB to conventional EEP transmission scheme which provided by RCM code.UEP protection scheme designed in this paper can be transmitted in real time to adapt to the channel, to overcome the effects of the video quality level, to achieve a smooth and efficient transmission of video quality, and the scheme does not need to change the video encoding structure which is conducive to compatibility with existing air interface.