基于方向调制的无线安全传输基本原理、关键技术与未来展望

方向调制(Directional modulation,DM)作为无线物理层安全传输的关键技术能够很好地提升系统的安全性能。然而,由于在角度测量过程中存在误差,因此需要在设计有用信号波束成形向量和人工噪声(Artificial noise,AN)投影矩阵时考虑角度误差,从而提升系统安全性能。本文首先描述了DM系统模型,然后介绍了到达角(Direction of arrival,DOA)估计技术、稳健波束成形设计的3种算法及功率分配技术。仿真表明:稳健波束成形合成方法的性能明显要优于非稳健合成方法,且有用信号和AN之间最优功率分配能明显提高安全速率性能。最后,对DM未来新的发展方向与所面临的挑战性等开放问题进行展望与总结。

Basic Principles, Key Technologies, and Future Prospects of Wireless Security Transmission Based on Directional Modulation

Directional modulation (DM), as the key technology of wireless physical layer security transmission, can improve the secrecy performance of the system. However, due to the angle measurement error, we need to consider the angle error to improve system security performance when designing useful signal beamforming vector and artificial noise (AN) projection matrix. The paper first describes system model of DM. Then we introduce the direction of arrival (DOA) estimation technique, three algorithms of robust beamforming design and power allocation technology. Simulations show that the performance of the robust beamforming synthesis method is obviously better than that of the non-robust synthesis method, and the optimal power allocation between the confidential information and the AN can significantly improve the security rate performance. Finally, the future new research directions and challenging problems are presented.