1,220 research outputs found
Secrecy outage analysis for Alamouti space-time block coded non-orthogonal multiple access
This letter proposed a novel transmission technique for physical layer security by applying the Alamouti Space-Time Block Coded Non-orthogonal Multiple Access (STBC-NOMA) scheme. The secure outage performance under both perfect successive interference cancellation (pSIC) and imperfect successive interference cancellation (ipSIC) are investigated. In particular, novel exact and asymptotic expressions of secrecy outage probability are derived. Numerical and theoretical results are presented to corroborate the derived expressions and to demonstrate the superiority of STBC-NOMA and its ability to enhance the secrecy outage performance compared to conventional NOMA
Location-Based Beamforming for Rician Wiretap Channels
We propose a location-based beamforming scheme for wiretap channels, where a
source communicates with a legitimate receiver in the presence of an
eavesdropper. We assume that the source and the eavesdropper are equipped with
multiple antennas, while the legitimate receiver is equipped with a single
antenna. We also assume that all channels are in a Rician fading environment,
the channel state information from the legitimate receiver is perfectly known
at the source, and that the only information on the eavesdropper available at
the source is her location. We first describe how the beamforming vector that
minimizes the secrecy outage probability of the system is obtained,
illustrating its dependence on the eavesdropper's location. We then derive an
easy-to-compute expression for the secrecy outage probability when our proposed
location-based beamforming is adopted. Finally, we investigate the impact
location uncertainty has on the secrecy outage probability, showing how our
proposed solution can still allow for secrecy even when the source has limited
information on the eavesdropper's location.Comment: 6 pages, 4 figure
Safeguarding Massive MIMO Aided HetNets Using Physical Layer Security
This paper exploits the potential of physical layer security in massive
multiple-input multiple-output (MIMO) aided two-tier heterogeneous networks
(HetNets). We focus on the downlink secure transmission in the presence of
multiple eavesdroppers. We first address the impact of massive MIMO on the
maximum receive power based user association. We then derive the tractable
upper bound expressions for the secrecy outage probability of a HetNets user.We
show that the implementation of massive MIMO significantly improves the secrecy
performance, which indicates that physical layer security could be a promising
solution for safeguarding massive MIMO HetNets. Furthermore, we show that the
secrecy outage probability of HetNets user first degrades and then improves
with increasing the density of PBSs
Fundamental properties of on-off transmission scheme for wiretap channels
This work reveals some fundamental properties of
an on-off transmission (OOT) scheme, in which a transmitter
sends signals occasionally as per the capacity of the main channel
in order to achieve physical layer security. To this end, we first
identify the widely used hybrid secrecy outage probability as
a function of the transmission probability and the conditional
secrecy outage probability of the OOT scheme. This indicates,
for the first time, that the hybrid secrecy outage probability
can be achieved by the OOT scheme. We then derive a lower
bound on the conditional secrecy outage probability of the OOT
scheme in case of transmission, which is solely determined by
the average signal-to-noise ratios (SNRs) of the main channel
and eavesdropper’s channel. Finally, we re-investigate the OOT
scheme within an absolutely completely passive eavesdropping
scenario, in which even the average SNR of the eavesdropper’s
channel is not required. Specifically, we derive an easy-evaluated
expression for the average conditional secrecy outage probability
of the OOT scheme by adopting an annulus threat model.ARC Discovery Projects Grant DP150103905
Optimal Power Allocation for A Massive MIMO Relay Aided Secure Communication
In this paper, we address the problem of optimal power allocation at the
relay in two-hop secure communications under practical conditions. To guarantee
secure communication during the long-distance transmission, the massive MIMO
(M-MIMO) relaying techniques are explored to significantly enhance wireless
security. The focus of this paper is on the analysis and design of optimal
power assignment for a decode-and-forward (DF) M-MIMO relay, so as to maximize
the secrecy outage capacity and minimize the interception probability,
respectively. Our study reveals the condition for a nonnegative the secrecy
outage capacity, obtains closed-form expressions for optimal power, and
presents the asymptotic characteristics of secrecy performance. Finally,
simulation results validate the effectiveness of the proposed schemes
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