Abstract: In order to improve the effectiveness of mobile cloud computing in Device-to-Device (D2D) communication network, a computation offloading scheme based on the time switch policy for energy harvesting was proposed. Firstly, the computational tasks needed to be migrated of a traffic-limited smart mobile terminal were sent to an energy-limited smart mobile terminal in the form of Radio-Frequency (RF) signals through D2D communication, and the time switch policy was used by the energy-limited smart mobile terminal for the energy harvesting of received signals. Then, the extra traffic consumption was paid by the energy-limited terminal for the relay tasks of traffic-limited terminal to the cloud server. Finally, the proposed scheme was modeled as a non-convex optimization problem for minimizing terminal energy and traffic consumption, and the optimal scheme was obtained by optimizing the time switch factor and the harvest energy allocation factor of the energy-limited terminal, and the transmission power of the traffic-limited terminal. The simulation results show that, compared with non-cooperative scheme, the proposed scheme can effectively reduce the terminal's limited resource overhead by the computation offloading through reciprocal cooperation.

Key words: mobile cloud computing, computation offloading, Device-to-Device (D2D) communication, Radio-Frequency (RF) energy harvesting, time switch policy

摘要： 在端到端（D2D）通信网络中，为提高移动云计算的有效性，提出了一种基于时间转换能量采集的计算迁移方案。首先，一个流量受限的智能移动终端把其需要迁移的计算任务通过D2D通信以射频信号的形式发送给一个能量受限的智能移动终端，后者利用时间转换方案对接收信号进行能量采集。然后，能量受限终端会为流量受限终端中继任务到云端服务器付出额外的流量消耗。最后，所提的方案被建模为一个最小化终端能量与流量消耗的非凸优化问题，通过优化能量受限终端的时间转换因子、采集能量分配因子以及流量受限终端的传输功率，最终获得了最优方案。仿真结果表明，相比于非协作方案，所提方案通过互惠协作进行计算迁移能有效地减少终端的匮乏资源开销。

关键词: 移动云计算, 计算迁移, 端到端通信, 射频能量采集, 时间转换方案