基于多径信道随机延时的物理层全算法

Security method of wireless physical layer security based on multipath channel random delay

针对无线通信遇到的第三方窃听问题,利用无线通信系统信道多径延时丰富的特征,提出了一种保证物理层安全传输的加密算法。该算法中,数据发送用户根据估计的多径延时信息随机提前符号发送时间,使授权用户的同步位置有较强的多径信号到达,授权接收用户在保持同步状态不变的情况下可以正常接收信息。而窃听用户具有不同的信道多径延时特征,接收到的信号幅度和相位会随机变化,难以进行同步跟踪,因此接收到的符号会产生大量的误码,从而提高授权用户之间的安全传输性能。仿真结果表明,该算法能有效提高窃听方的误码率,提高授权用户通信的安全性,从而可在多径环境中有效保证物理层通信安全。

For the wire-tapping in wireless communication system, this paper presented an encrypting method based on chan- nel multipath delay-time information to ensure the security of physical layer in wireless communication system. In this method, the transmitter made the time to transmit symbol random with channel multipath delay-time information that estimated, and made the received signal of legitimate receiver stronger at the synchronization location. So the legitimate could receive the information normally. While the received signal of eavesdropper turned random for different channel information, such as phase and range. Then the eavesdropper couldn＇ t recover the information with the random received signal, and the error probability was high,which increased the security of legitimate receiver. The simulations show that the method can keep the eavesdropper＇ s error probability at a high level, so as to increase the system security. Finally, it comes to the conclusion that this method can ensure the security of physical layer in wireless communication system with channel multipath.