Intrinsic Interference Based Physical Layer Encryption for OFDM/OQAM

A physical layer encryption method is proposed for orthogonal frequency division multiplexing with offset quadrature amplitude modulation. The proposed method uses intentionally added pure imaginary symbols as keys, so that their intrinsic interferences can obfuscate true data symbols at the eavesdroppers. The key generation method and four loading patterns are proposed. Also, the impact of channel estimation error, the robustness against ciphertext attacks, and the information leakage at the eavesdropper are analyzed. Finally, the performance of the proposed method is evaluated through numerical simulations.