Performance Analysis for Coded Wireless Steganography System with OFDM Signaling

We investigate the performance of a physical layer security technique based on wireless steganography, where orthogonal frequency division multiplexing (OFDM) signal that carries private information is embedded within the single-carrier (SC) cover signal that broadcasts public information. The legitimate receiver employs successive interference cancellation (SIC) similar to that of power domain non-orthogonal multiple access (PD-NOMA), where it first decodes the public information, and then decodes secret information from the embedded OFDM signal after subtraction of the cover SC signal. For a given power ratio of the two signals, the achievable information rate of embedded data is analyzed, and the trade-off relationship among the two information rates and power ratio is confirmed by the computer simulation in terms of the coded bit error rate (BER) performance. We also evaluate the secrecy capacity if the wiretap channel model is applied to our system.