Research On Key Techniques Of Radio Resource Allocation In Relay-enhanced Cellular Networks

With the continuous development of network technology and hardware equipment, existing network bandwidth and terminal equipment showing a trend of diversification which presents new challenges to video codec technology. In response to the differences in bandwidth and processing capacity and resolution of the terminal, ITUT and ISO/IEC Joint Video Experts Group(JVT) proposed H.264/AVC scalable video coding(SVC) extension in 2007. SVC can be selectively discarded during transmission or at the end portion to meet terminal needs of certain frame rate or resolution or quality. A video sequence can be coded once with several combined frame rate, resolution and quality by SVC, of which any combination stream can be decoded to playback or transfer as needed.SVC can adapt to different channel and endpoint device, but it’s implemented by discarding parts of the stream, which will inevitably lead to reduction of the whole information. Thus it is necessary to research SVC bit allocation and rate control. This thesis mainly studies SVC rate control and transmission, detailed contents are as follows:1. Analysis on the scalability of SVC in time, space, and quality and their implementation. Discussion on existing frame rate control technology of GOP level, frame level and basic unit level. Brief introduction to the video transmission technology.2. Researched the implementation of time scalability(Hierarchical B structure), and proposed a frame-level constant rate control method. The amount of bits by the method of assigning different time frame level for different proportions of rate control, and the difference between the value of the budget and the actual encoding bits of each frame taking into account of frames in the future coding, thus ensuring the overall rate accuracy. Updated bit allocation for each frame within a GOP after finishing coding prefix GOP to improve the accuracy and stability of the quality of each frame budget.3. Researched joint constant quality rate control of scalable video coding and proposed an advanced constant quality control for Hierarchical B structure and spatial enhancement layers based on the peak signal to noise ratio(PSNR), the spatial enhancement layer adjust it prediction QP according to the lower level coding results to improve its prediction accuracy.4. Researched transmission technology of audio and video data and adaptive level SVC encoded video switching method in transmission. Using RTP/RTCP protocol for audio and video transmission and control, including the synchronization of video and audio control and adaptive SVC bit stream switching control.