无人机辅助无线通信位置和波束联合优化方法

Joint optimization method of position and beam for UAV aided wireless communication

无人机辅助无线通信具有部署灵活,覆盖范围大等优势,但仍存在路径损耗大,吞吐量和传输能力低的缺点。将波束赋形技术引入无人机辅助无线通信中,可以有效补偿通信路径损耗,缓解小区内或小区间干扰。因此,本文面向无人机辅助无线通信系统,在地面基站和无人机上配备均匀平面阵列来实现波束赋形,以最大化系统容量。针对优化变量高维且高度耦合的非凸问题,提出了一种高效迭代算法来联合优化中继无人机位置和波束赋形向量,首先通过块坐标下降法将原问题转化为中继无人机位置优化和波束赋形向量优化两个子问题,然后利用连续凸逼近算法将两个子问题转化为凸优化问题进行求解。实验结果表明,所提的优化理论和算法具有较好的收敛性能,并且能够切实提高系统容量。

UAV aided wireless communication has the advantages of flexible deployment and large coverage,but it still has the disadvantages of large path loss,low throughput and transmission capacity.Beamforming technology is introduced into UAV aided wireless communication,which can effectively compensate the communication path loss and mitigate intra cell or inter cell interference.Therefore,this paper constructs a UAV aided wireless communication system model,which is equipped with a uniform plane array on the ground base station and UAV to achieve beamforming,so as to maximize the system capacity.For the nonconvex problem with high dimensional and highly coupled optimization variables,an efficient iterative algorithm is proposed to jointly optimize the position of the relay UAV and beamforming vector.Firstly,the original problem is transformed into two subproblems of the position optimization of the relay UAV and beamforming vector optimization by the block coordinate descent method,and then the two subproblems are transformed into a convex optimization problem by the successive convex approximation algorithm.Experimental results show that the proposed optimization theory and algorithm have good convergence performance and can effectively improve system capacity.