无人机辅助蜂窝网络中的无人机与用户协同缓存算法

Cooperative caching algorithm of UAV and user in UAV-assisted cellular network

针对无人机辅助蜂窝网络中的海量数据内容传输与无人机无线回程带宽受限这一矛盾,提出了一种无人机与用户协同缓存算法。通过在无人机以及用户设备上部署存储设备,将用户请求的热点内容缓存后进行共享分发,以减少无人机回程链路资源与能量开销,减轻业务负载并降低用户时延。以用户内容获取时延最小化为目标建立了无人机与用户缓存联合优化问题,将其分解为无人机缓存子问题与用户缓存子问题,并分别基于交替方向乘子法和全局贪婪算法进行求解,通过迭代获得收敛的优化结果,实现了无人机与用户的协同缓存。仿真结果表明,所提算法能够有效降低用户的内容获取时延,提升系统性能。

Aiming at the problem of mass data content transmission and limited wireless backhaul resource of UAV in UAV-assisted cellular network,a cooperative caching algorithm for cache-enabled UAV and user was proposed.By deploying caches on UAV and user device,the popular content requested by user was cached and delivered,which alleviated the backhaul resource and energy consumption of UAV,reduced the traffic load and user delay.A joint optimization problem of UAV and user caching was established with the goal of minimizing user content acquisition delay,and decomposed into UAV caching sub-problem and user caching sub-problem,which were solved based on alternating direction method of multiplier and global greedy algorithm respectively.The iterative way was used to obtain convergent optimization result,and the cooperative caching of UAV and user was realized.Simulation results show that the proposed algorithm can effectively reduce user content acquisition delay and improve system performance.