干扰环境下面向NOMA的多无人机中继通信资源联合优化方法

Joint optimization method for multi-UAV relay communication resources facing NOMA under interference conditions

摘要:

针对干扰环境中频谱资源稀缺和通信质量下降的挑战,考虑利用无人机(unmanned aerial vehicle, UAV)的灵活部署和非正交多址接入(non-orthogonal multiple access, NOMA)的高频谱利用率优势,提出了一种干扰条件下多UAV辅助下行NOMA网络的 UAV位置、用户匹配、信道分配和功率分配联合优化方法。首先,利用麻雀搜索算法(SSA)随机生成个体信息,将每个个体映射为多个无人机的三维坐标。其次,通过UAV信息和用户位置信息,对UAV的坐标按照需要匹配的用户数量进行虚拟点扩展,利用最大权匹配方案,结合NOMA两用户最优功率分配系数和信道分配方案计算用户的和速率,计算最大权值作为麻雀个体的适应度值。最后,将获得的不同麻雀个体的适应度值代入SSA中,寻找最优麻雀个体,来提高系统的和速率。仿真结果表明,该方法与基准算法相比,能够有效提升所有用户的和速率,为干扰条件下NOMA接入的多UAV中继通信提供了一种和速率优化的解决方案。

Abstract:

In response to the challenges of scarce spectral resources and declining communica tion quality in interference environments, considering the advantages of flexible deployment of unmanned aerial vehicles (UAV) and the high spectral efficiency of non-orthogonal multi ple access (NOMA), this paper proposed a joint optimization method for multi-UAV positio ning, user matching, channel allocation and power allocation in multi-UAV assisted downlink NOMA networks under interference conditions. Firstly, the sparrow search algorithm(SSA) was used to randomly generate individual information, mapping each individual to the 3-D co ordinates of multiple UAVs. Then, through the UAV information and user location data, the coordinates of the UAV were extended with virtual points according to the number of users that need to be matched. Using the maximum weight matching scheme, combined with the optimal power allocation coefficient and channel allocation scheme of NOMA for two users, the user’s sum-rate was calculated. Finally, the the obtained fitness values of different spar row individuals were brought into the SSA to find the optimal sparrow individual,thereby im proving the sum-rate of the system. Simulation results indicate that, compared to the base line algorithms, this method can significantly improve the sum-rate of all users, which pro vides a solution for optimizing the sum-rate in multi-UAV relay communications with NOMA access under interference conditions