Technology Independent Security Aware OFDM (SA-OFDM)

Orthogonal frequency division multiplexing (OFDM) is currently the most prominent modulation technique, mainly due to it's spectral efficiency. To improve the security performance of OFDM based systems, multiple security approaches are proposed in literature, including physical-layer (PHY) approaches. However, these techniques are technology specific, i.e. mostly designed for radio frequency (RF) transmission and cannot be directly deployed in other technologies such as optical wireless communications (OWC). In this paper, security aware OFDM (SA-OFDM) is presented as a technology independent PHY security approach designed to suppress eavesdropping. The novelty of SA-OFDM is not only its versatility in deployment, but also in its perception in combining PHY encryption and the receiver's architecture to improve security performance. SA-OFDM is tested under additive white Gaussian noise (AWGN) and Rayleigh channel models, indicating negligible impact on system performance for both RF and OWC links. Results show that the eavesdropper becomes oblivious to the transmitted information, i.e. has a bit-error-rate (BER) of 0.5, which is equivalent to random guessing. Even if the key is seized, the eavesdropper's BER does not exceed 10^-2.