Artificial Noise Shielded Frequency-Hopping Systems: Transceiver Design and Performance Analysis

To further protect frequency-hopping (FH) systems against severe wiretapping, an architecture of artificial noise (AN) shielded FH systems (ANS-FH) is proposed, wherein an AN cancellation architecture is utilized at the authorized receiver, and the secrecy performance is analyzed in the presence of an eavesdropper. First, an inter-frequency interference (IFI) model is employed to depict the residual AN after AN cancellation. Then, the tolerable range of frequency deviation is given, and the signal to AN plus noise ratio (SANR) is provided to measure the AN cancellation performance. Finally, the secrecy performance is analyzed using secrecy capacity under the assumption that frequency deviation is uniformly distributed within frequency synchronization accuracy. Theoretical and simulation results confirm that frequency deviation in practical FH systems will degrade both AN cancellation and system secrecy performance, and shorter hop length or proper power allocation for secret data and AN can mitigate the negative impact of frequency deviation, which in turn guides the practical transceiver design.