基于AMC的可伸缩视频多播中调制编码方案分配

受限于频谱资源有限性以及无线链路质量差异性,有效的编码调制方案成为视频多播中亟需考虑的关键问题,选择先进的信源编码以及自适应编码调制技术能够有效降低信道差异造成的影响。提出一种适用于带宽无线网络的分层视频多播传输策略。该策略将自适应调制编码(AMC)与可伸缩视频编码(SVC)相结合,首先将系统效用函数表示为与用户接收速率相关的通用效用函数,通过使用平均分配方法为多播视频流分配一定的无线资源,使用遗传算法为每个视频流的视频层选择一种合适的调制编码方案(MCS),同时为了提高算法收敛特性,在目标函数中引入了动态惩罚项。最后将该算法与已提出的贪婪算法以及启发式算法进行比较,仿真结果表明,提出的用于解决视频层调制编码方案选择的遗传算法能够有效的提高系统性能,为用户提供更好的视频服务质量(QOS)。

Distribution of modulation and coding scheme for scalable video multicast based on AMC

Due to the limited spectrum resource and the difference between wireless link qualities, efficient modulation and coding scheme becomes a key issue needed to consider in video multicast. Advanced source coding and Adaptive Modulation and Coding (AMC) technology can effectively reduce the influence of channel difference. In this paper, a layered video multicast scheme for broadband wireless network is proposed. This multicast scheme works by combining Scalable Video Coding (SVC) with Adaptive Modulation and Coding. The system utility is formulated into a function of received rate. By the average allocation scheme, allocate radio resources for each video streaming in the first. Then, select an appropriate modulation and coding scheme for each video layer by genetic algorithm. Meanwhile, in order to improve the convergence properties of the algorithm, a dynamic penalty term is presented in the utility function. Finally, this algorithm is compared with the greedy algorithm and heuristic algorithm. The simulation results show that the proposed algorithm in this paper can achieve a better performance and provide a better video quality of service (QOS) for the users.