Joint beamforming and admission control for cache-enabled Cloud-RAN with limited fronthaul capacity
Joint beamforming and admission control for cache-enabled Cloud-RAN with limited fronthaul capacity
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DOI：
10.1049/iet-spr.2019.0247
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发表时间：
2020-03
期刊：
影响因子：
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通讯作者：
Ashraf Bsebsu;G. Zheng;S. Lambotharan;K. Cumanan;Basil AsSadhan
中科院分区：
文献类型：
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作者：
Ashraf Bsebsu;G. Zheng;S. Lambotharan;K. Cumanan;Basil AsSadhan
缓存是云无线接入网（Cloud-RAN）减轻前传链路中的业务负载问题的有前途的解决方案。多用户下行波束赋形对于有效利用频谱和传输功率，同时满足用户的服务质量（QoS）要求起着重要的作用。当用户数量超过网络的服务容量时，某些用户将不得不被丢弃或重新调度。这通常通过适当的准入控制机制来实现。引入本地存储或缓存在远程无线电头端（RRH），其中一些流行的内容被缓存，我们提出了波束成形和准入控制技术的缓存使能的云RAN在下行链路中。这最小化了总网络成本，包括功率和前传成本，同时允许尽可能多的用户。我们制定这个多目标优化问题作为一个单目标优化问题。首先将原混合整数非线性规划问题转化为混合整数二阶锥规划问题。然后使用分支定界（BnB）算法来确定最优解和次优解。仿真研究已经进行了评估这两种方法的性能。
Caching is a promising solution for the cloud radio access network (Cloud-RAN) to mitigate the traffic load problem in the fronthaul links. Multiuser downlink beamforming plays an important role for efficient utilization of spectrum and transmission power while satisfying the user’s quality of service (QoS) requirements. When the number of users exceeds the serving capacity of the network, certain users will have to be dropped or re-scheduled. This is normally achieved by appropriate admission control mechanisms. Introducing local storage or cache at the remote radio heads (RRHs) where some popular contents are cached, we propose beamforming and admission control technique for cache-enabled Cloud-RAN in the downlink. This minimizes the total network cost including power and fronthaul cost while admitting as many users as possible. We formulate this multi-objective optimization problem as a single objective optimization problem. The original problem which is mixed-integer non-linear program (MINLP) is first co verted to the mixed-integer second order cone programming form (MISOCP). Branch and Bound (BnB) algorithm is then used to determine the optimal and suboptimal solutions. Simulation study has been conducted to assess the performance of both methods.