QoE-Aware Transmission Control Policy For Device-To-Device Video Sharing With Low Energy Consumption

In the next generation wireless communication system, common cellular users are allowed to share video resources through device-to-device(D2D) communication technique, which can be assisted by the cellular base station(BS). However, the high energy consumption during D2 D video sharing may reduce the duration of D2 D video sharing and kill the motivation of the D2 D users due to the energy shortage of the mobile devices. Therefore, it is of great significance to reduce the energy consumption while guaranteeing the quality of experience(QoE) of D2 D users during D2 D communication. The main content of this thesis is introduced as follows.Under the scenario that multiple D2 D pairs are conducting D2 D on-demand variable bit rate(VBR) video sharing with the full control of the BS, a control policy is proposed in order to reduce the overall transmission energy consumption while guaranteeing the video playback fluency for each D2 D pair. At first, the problem is formulated as a stochastic program that is with time coupling property. Then, we relax the original problem appropriately in order to remove the time coupling property. Suffering from the unknown stochastic knowledge of the D2 D channel states and inspired by the Lyapunov optimization technique, we convert the relaxed problem into a queueing stability problem via constructing a delay virtual queue that is based on the playback duration of the real time buffered data for each D2 D pair. Then, the corresponding operation algorithm is proposed.Through carefully selecting a valid control parameter, the feasibility of the proposed control policy to the original problem is guaranteed. Then, the performance analysis is provided to demonstrate the feasibility and the effectiveness of the proposed control policy theoretically. Last but not the least, the trace-driven simulation evaluation based on realistic VBR video traffic is conducted and simulation results show the performance gain of the proposed control policy against the baseline policies.