隐藏有限字符特性的跳空安全传输方法

摘要

针对无线数字通信系统，从信息论角度推导了一个保障物理层安全传输的充分条件，并提出了一种隐藏有限字符特性的跳空安全传输方法。首先，在有限字符输入系统中，多天线窃听者具有离散有噪无损信道（Discrete Noisy Lossless Channel ，DNLC ）结构，可以恢复保密信号，致使人工噪声方法失效，因此破坏窃听者的DNLC结构是保证系统传输安全的一个充分条件。然后，利用无线信道特征的多样性和独特性，提出一种基于多输入多输出（Multiple In-put Multiple Output ，MIMO）系统的跳空安全传输方法，在传输信息的过程中随机切换收发天线并发送空域干扰，可以隐藏保密信号的有限字符特性并破坏窃听者的DNLC结构。最后，理论分析和仿真结果表明了该安全方法的有效性。%Addressing the wireless digital communication system ,a sufficient condition to ensure the physical-layer security transmission is derived from the viewpoint of information theory ,and a space hopping secure transmission method is proposed ,which can mask the characteristic of finite alphabets .First ,since the multi-antenna eavesdropper in the finite-alphabet-input system possess-es the architecture of Discrete Noisy Lossless Channel (DNLC) ,it can reconstruct the secret signal and invalidate the artificial noise method .As a result ,destroying the eavesdropper ’ s DNLC architecture becomes a sufficient condition for ensuring the security of system transmission .Then ,utilizing the diversity and uniqueness of wireless channel characteristics ,a space hopping secure transmis-sion method based on the Multiple Input Multiple Output (MIMO) system is proposed .It switches receiver/transmitter antennas and transmits spatial scrambling during the information transmission ,which can mask the finite alphabet characteristic of the secret signal and destroy the eavesdropper’s DNLC architecture .Finally ,theoretical analysis and simulation results demonstrate the efficacy of the secure method .