Cyclic Feature Concealing CP Selection for Physical Layer Security

Cyclic prefix (CP) utilizing techniques such as orthogonal frequency division multiplexing (OFDM) and single carrier frequency domain equalization (SC-FDE) offer significant advantages in equalizing the effect of time dispersive channels at the expense of a reasonable spectral redundancy. However, cyclic features introduced by CP to the signal can also be exploited for blind parameter estimation and synchronization which compromise the security and privacy of the signal against eavesdropping attacks. In this paper, we propose a novel CP selection technique that conceals the cyclic features of the signal while maintaining the advantages in equalization without reducing spectral efficiency. After presenting the proposed technique, its performance is discussed for OFDM and SCFDE in terms of bit-error rate and complexity as well as cyclic feature suppression.