Physical-Layer-Security-based OFDM Transmission with Phase Error Insertion

Abstract

In recent years, orthogonal frequency division multiplexing has been considered a potential technology for serving as a source of randomness for the physical layer security designs due to the high dimensionality per single transmission represented by the modulated subcarriers. In this paper, we first proposed an algorithm with a pre-shared key to rotate the constellation mapping of the modulated M-ary phase shift keying M-PSK symbols. Following this, we exploited the independent channel fading of the subcarriers by inducing a phase error per symbol based on the channel state information to make the cryptographic attacks more challenging. The bit mismatch was then minimised through error-correcting codes. The security’s efficacy can be evaluated by the symbol error rate as a false cipher detection rate. The simulation results indicated that the attacker’s receiver suffers higher detection errors of the cipher even when the received signal-to-noise ratio is the same as that of the legitimate users.