Power Allocation and Artificial Noise Design of Time-Reversal OFDM System to Enhance Security Performance
Time reversal technology has natural anti-eavesdropping capability due to its unique spatial and temporal focusing capability.In this paper,an optimization scheme to improve the security performance of time reversal OFDM system is studied.Firstly,the temporal and spatial focusing characteristics of time reversal pre-filtering are applied to im-prove the signal strength of the legitimate receiver relative to the eavesdropper,and then the power of the subcarriers is op-timized to maximize the security rate.In order to further improve the secure capability of the system,the zero-space artifi-cial noise is realized by employing the degree of freedom provided by the circular prefix,which can effectively interfere with the eavesdropper,while does not interfere with the legitimate receiver.Then,the subcarrier power and the covariance matrix of the artificial noise are optimized to maximize the security transmission rate.Simulation results show that the pro-posed scheme can significantly promote the security rate of the system.
physical layer securityorthogonal frequency division multiplexingtime reversalpower allocationarti-ficial noise
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