Xu Zhengjia, Petrunin Ivan, Tsourdos Antonios
School of Aerospace, Transport and Manufacturing, Cranfield University, Cranfield MK43, UK.
Sensors (Basel). 2021 Jan 13;21(2):534. doi: 10.3390/s21020534.
In anticipation of wide implementation of 5G technologies, the scarcity of spectrum resources for the unmanned aerial vehicles (UAVs) communication remains one of the major challenges in arranging safe drone operations. Dynamic spectrum management among multiple UAVs as a tool that is able to address this issue, requires integrated solutions with considerations of heterogeneous link types and support of the multi-UAV operations. This paper proposes a synthesized resource allocation and opportunistic link selection (RA-OLS) scheme for the air-to-ground (A2G) UAV communication with dynamic link selections. The link opportunities using link hopping sequences (LHSs) are allocated in the GCSs for alleviating the internal collisions within the UAV network, offloading the on-board computations in the spectrum processing function, and avoiding the contention in the air. In this context, exclusive technical solutions are proposed to form the prototype system. A sub-optimal allocation method based on the greedy algorithm is presented for addressing the resource allocation problem. A mathematical model of the RA-OLS throughput with above propositions is formulated for the spectrum dense and scarce environments. An interference factor is introduced to measure the protection effects on the primary users. The proposed throughput model approximates the simulated communication under requirements of small errors in the spectrum dense environment and the spectrum scarce environment, where the sensitivity analysis is implemented. The proposed RA-OLS outperforms the static communication scheme in terms of the utilization rate by over 50 % in case when multiple links are available. It also enables the collaborative communication when the spectral resources are in scarcity. The impacts from diverse parameters on the RA-OLS communication performance are analyzed.
鉴于5G技术的广泛应用，无人机通信频谱资源的稀缺仍然是安排安全无人机作业的主要挑战之一。作为一种能够解决这一问题的工具，多架无人机之间的动态频谱管理需要综合解决方案，考虑异构链路类型并支持多无人机作业。本文提出了一种用于空对地（A2G）无人机通信的综合资源分配和机会链路选择（RA-OLS）方案，该方案具有动态链路选择功能。利用链路跳变序列（LHS）分配链路机会，以减轻无人机网络内部的冲突，减轻频谱处理功能中的机载计算负担，并避免空中的竞争。在此背景下，提出了专门的技术解决方案以形成原型系统。提出了一种基于贪心算法的次优分配方法来解决资源分配问题。针对频谱密集和稀缺环境，建立了具有上述命题的RA-OLS吞吐量数学模型。引入干扰因子来衡量对主要用户的保护效果。所提出的吞吐量模型在频谱密集环境和频谱稀缺环境下小误差要求下近似模拟通信，并进行了敏感性分析。在有多条链路可用的情况下，所提出的RA-OLS在利用率方面比静态通信方案高出50%以上。当频谱资源稀缺时，它还能实现协作通信。分析了各种参数对RA-OLS通信性能的影响。
