MISO无线携能通信系统保密波束形成方法

Secure beamforming method for the MISO SWIPT system

为有效应对多输入单输出(multiple input single output,MISO)无线携能通信(simultaneous wireless information and power transfer,SWIPT)系统中的信息安全问题,提出人工噪声(artifical noise,AN)辅助的波束形成方案,并进一步将这一问题表述为用户需求限制的功率控制问题。然而,该问题具有典型的非凸复杂性,其最优解无法在多项式时间内得到有效解决。为此,基于必要简化,提出了双层优化算法来快速求取其次优解;同时,又进一步把该双层算法推广到非理想信道条件下,构建了鲁棒波束形成方法。仿真实验表明,与经典迫零算法相比,双层算法具有更好的性能,且更具鲁棒性;而且,随着信道估计误差的增加,双层优化算法的优势更加明显。

To solve the information security issue in the multiple input single output(MISO)simultaneous wireless information and power transfer(SWIPT)system,an artificial noise(AN)-aided beamforming scheme is proposed,and further formulating the problem as a power control problem under user requirement constraint.However,this problem is of huge non-convex complexity and cannot be solved in polynomial time.Therefore,an efficient two-tier algorithm is developed for a sub-optimal solution,which is extended further to the imperfect channel conditions for a robust beamforming scheme.Simulation results show that the two-tier algorithm has better performance and more robustness when compared with the classic zero-forcing(ZF)algorithm,and the advantage of it is more obvious as the channel estimation error increases.