1 research outputs found
Exploiting Direct Links for Physical Layer Security in Multiuser Multirelay Networks
We present two physical layer secure transmission
schemes for multi-user multi-relay networks, where the
communication from M users to the base station is assisted
by direct links and by N decode-and-forward relays. In this
network, we consider that a passive eavesdropper exists to
overhear the transmitted information, which entails exploiting
the advantages of both direct and relay links for physical layer
security enhancement. To fulfill this requirement, we investigate
two criteria for user and relay selection and examine the
achievable secrecy performance. Criterion I performs a joint user
and relay selection, while Criterion II performs separate user
and relay selections, with a lower implementation complexity.
We derive a tight lower bound on the secrecy outage probability
for Criterion I and an accurate analytical expression for the
secrecy outage probability for Criterion II. We further derive
the asymptotic secrecy outage probabilities at high transmit
signal-to-noise ratios and high main-to-eavesdropper ratios for
both criteria. We demonstrate that the secrecy diversity order
is min (MN;M + N) for Criterion I, and N for Criterion II.
Finally, we present numerical and simulation results to validate
the proposed analysis, and show the occurrence condition of the
secrecy outage probability floor.ARC Discovery Projects Grant DP150103905