Compressive sensing based decryption method for covert CDD-OFDM transmission

This paper presents an improved decryption method aiming at covert Orthogonal Frequency Division Multiplexing (OFDM) transmission with cyclic delay diversity (CDD) featured multiple input multiple output (MIMO) technology. Particularly, we take advantage of the inherent sparse structure of multi-path wireless channel as well as Compressive Sensing (CS) technology, which has attracted a considerable attention for its breakthrough on Shannon´s sampling theorem. Our work addresses the issues of bounded application range for conventional decryption methods, which is caused by the limitation of channel estimation with respect to uneven pilot arrangement that employed as a physical layer secret key. Besides, our proposed method relaxes minimum requirement for pilot number while the performance gain is improved instead. Simulation results show that our proposed method can achieve a considerable performance gain, with extra rewards of high spectral efficiency and much broader application prospect.