Cross-layer optimised high-definition video multicast in TV whitespace

Wireless video multicast is a newly arising technique for video transmission. This type of transmission technology requires a large amount of spectrum resources to transmit data. Using TV whitespace for video multicast can not only solve the problem of wireless video multicast, but also can effectively increase the spectrum utilization of TV whitespace. For the purpose of the overall received video quality, this paper presents a study of optimised real-time video multicast in TV Whitespace. Firstly, we suggest a practical and bandwidth efficient TV Whitespace video multicast framework. Under the framework, we model the TV Whitespace video multicast as a cross-layer optimisation problem, which a quasi-static spectrum access scheme based on TV whitespace is proposed to solve the problem of excessive time delay caused by frequent spectrum switching. Furthermore, considering various cross-layer design factors, adaptive modulation coding (AMC) is used in the PHY layer to improve transmission efficiency. In order to adjust the video rate equivalent to the channel conditions, scalable video coding (SVC) is exploited in our framework. Moreover, this article focuses on the issue of optimal resource scheduling, which introduce an innovative cross-layer optimised subcarrier scheduling mechanism for the TV whitespace video multicast system. The optimal scheduling problem is generalized by the scheme into a mixed integer nonlinear programming problem (MINLP), which meets the unique constraint, layer integrity constraints, limited allocation principle as well as the lower minimum rate limiting and other related real video transmission constraint. In addition, the heuristic algorithm of Binary Particle Swarm Optimisation (BPSO) is proposed by us to obtain the suboptimal solution of the optimal subcarrier scheduling problem. Finally, the effectiveness and superiority of this scheme are proved by our simulations.