2 research outputs found
Intelligent Interference Exploitation for Heterogeneous Cellular Networks against Eavesdropping
This paper explores the co-existence of a macro cell and a small cell for
heterogeneous cellular networks, where a macro base station (MBS) and small
base station (SBS) transmit to respective macro user (MU) and small user (SU)
through their shared spectrum in the face of a common eavesdropper. We consider
two spectrum sharing mechanisms, namely the overlay spectrum sharing (OSS) and
underlay spectrum sharing (USS). In the OSS, MBS and SBS take turns to access
their shared spectrum. By contrast, the USS allows MBS and SBS to
simultaneously transmit over the shared spectrum with the aid of power control
for limiting their mutual interference, thus called interference-limited USS
(IL-USS). In order to take advantage of mutual interference in confusing the
eavesdropper without causing adverse effect on the MU, we propose an
interference-canceled USS (IC-USS) scheme. Closed-form expressions of overall
outage probability and intercept probability are derived for OSS, IL-USS and
IC-USS schemes by taking into account both MBS-MU and SBS-SU transmissions. The
secrecy diversity analysis is also carried out by characterizing an asymptotic
behavior of the overall outage probability with a given intercept probability
in the high signal-to-noise ratio region. It is shown that the secrecy
diversity gains of conventional OSS and IL-USS are zero, whereas the proposed
IC-USS achieves a higher secrecy diversity gain of one. This implies that with
an arbitrarily low overall intercept probability, the conventional OSS and
IL-USS methods converge to their respective outage probability floors, however
the proposed IC-USS scheme can make the overall outage probability
asymptotically decrease to zero by simply increasing the transmit power.
Additionally, numerical results demonstrate an obvious advantage of the
proposed IC-USS over OSS and IL-USS against eavesdropping.Comment: 12 pages, IEEE Journal on Selected Areas in Communications, 201
Secrecy Outage and Diversity Analysis of Multiple Cooperative Source-Destination Pairs
We study the physical-layer security of a multiple source-destination (SD)
pairs coexisting wireless network in the face of an eavesdropper, where an
eavesdropper intends to wiretap the signal transmitted by the SD pairs. In
order to protect the wireless transmission against eavesdropping, we propose a
cooperation framework relying on two stages. Specifically, an SD pair is
selected to access the total allocated spectrum using an appropriately designed
scheme at the beginning of the first stage. The other source nodes (SNs)
simultaneously transmit their data to the SN of the above-mentioned SD pair
relying on an orthogonal way during the first stage. Then, the SN of the chosen
SD pair transmits the data packets containing its own messages and the other
SNs' messages to its dedicated destination node (DN) in the second stage, which
in turn will forward all the other DNs' data to the application center via the
core network. We conceive a specific SD pair selection scheme, termed as the
transmit antenna selection aided source-destination pair selection (TAS-SDPS).
We derive the secrecy outage probability (SOP) expressions for the TAS-SDPS, as
well as for the conventional round-robin source-destination pair selection
(RSDPS) and non-cooperative (Non-coop) schemes for comparison purposes.
Furthermore, we carry out the secrecy diversity gain analysis in the high
main-to-eavesdropper ratio (MER) region, showing that the TAS-SDPS scheme is
capable of achieving the maximum attainable secrecy diversity order