双用户分组上行多载波非正交多址接入的能耗最小化

Energy Minimization for Data Collection in UAV-assisted WSNs with Two-user Uplink Multi-carrier NOMA

为实现边境地区无线传感网长期工作,采用无人机与非正交多址(Non-Orthogonal Multiple Access,NOMA)技术结合的网络对分布在狭长边境线的传感器进行数据采集,以有效降低无线传感网(Wireless Sensor Networks,WSNs)的能耗。传感器用户组以多载波NOMA方式上传数据至无人机,在最大发射功率、用户服务质量(Quality of Service,QoS)及无人机移动性的约束下,通过优化传感器用户调度和分组、发射功率及无人机轨迹最小化所有传感器总能耗。该优化问题为混合整数非线性优化问题,将其分解为3个子问题求解。利用穷举搜索、拉格朗日对偶分解和逐次凸逼近(Successive Convex Approximation,SCA)依次求解各子问题并迭代优化,得到能耗最小值。仿真结果表明,所提方案可以有效降低无线传感网总能耗。

In order to achieve the long-term work of the wireless sensor network in the border area,a network combining UAV and NOMA(Non-Orthogonal Multiple Access)technology is used to collect data from sensors distributed along the narrow border,so as to effectively reduce the energy consumption of WSNs(Wireless Sensor Networks).The sensor user group uploads data to UAV in a multi-carrier NOMA mode to minimize the total energy consumption of all sensors by optimizing sensor user scheduling and grouping,transmit power and UAV trajectory under the constraints of maximum transmit power,user QoS(Quality of Service)and UAV mobility.The optimization problem is a mixed integer nonlinear optimization problem,which is decomposed into three subproblems to solve.By using exhaustive search,Lagrange duality decomposition and SCA(Successive Convex Approximation),the subproblems are solved successively,and the minimum energy consumption is achieved.Simulation results indicate that the proposed scheme can effectively reduce the total energy consumption of the WSNs.