一种基于投影的MIMO物理层安全传输方法

A Security Scheme of Physical Layer transmission based on Projection in MIMO Wireless Communication

为了保证MIMO系统无线传输安全,提出了一种基于投影的物理层安全传输方案。基站在合法信道的投影空间发射相互正交的涉密信号和干扰信号,干扰窃听方恢复信息,同时不影响期望用户接收信号。给出了两种信号保密容量准则下功率分配的迭代算法。通过分析干扰对窃听信号统计特性的影响,证明了对窃听方盲处理造成的不确定度(indeterminacy)。仿真结果表明,该方案具有较高的保密信道容量,在期望用户处获得比已有方案更低的误码率,而窃听方无法正确解调。

A scheme based on projection operator is proposed to guarantee the information theoretical security in MIMO physical layer transmission.The transmitter has multiple antennas and is able to simultaneously transmit separately information bearing signal to the intended receiver and randomized interference to the eavesdropper in the projection space.An iterative algorithm of power allocation between them is given according to the secret channel capacity criteria.Based on the special statistical distributions of the adversary’s received signal,the indeterminacy of its blind deconvolution is proved.Numerical results indicate that the secret channel capacity of this scheme is enhanced with reduced bit error rate at the target user,while the eavesdropper can not demodulate correctly.