28 research outputs found
Transmitter Selection for Secrecy Against Colluding Eavesdroppers with Backhaul Uncertainty
Due to the exponential growth of interconnected devices and reduced cell
coverage, beyond fifth-generation networks will be dense. Thus, instead of
wired backhaul, wireless backhaul will be cost-effective and flexible. For
security in multi-transmitter systems, sub-optimal and optimal transmitter
selection schemes exist. However, including backhaul activity knowledge
available (BKA) and backhaul activity knowledge unavailable (BKU) cases and
transmitter selection schemes, there is no generalized secrecy analysis method.
Moreover, evaluation of the ergodic secrecy rate (ESR) of the optimal selection
schemes is impossible using existing solution approaches. To address these, we
propose two sub-optimal and optimal transmitter selection schemes for a
small-cell multi-transmitter system in BKU or BKA cases in the presence of
multiple colluding eavesdroppers. We derive the distribution of the ratio of
the destination channel SNR and eavesdropping channel SNR, thereby providing
different secrecy performance metrics uniformly irrespective of selection
schemes and BKU or BKA cases. Simplified asymptotic expressions are provided to
elucidate the influence of the system parameters and of the backhaul
reliability. We observe that the secrecy performance improves when the
knowledge of backhaul link activity is utilized, and the improvement is most
noticeable when the backhaul is highly unreliable. We also observe that while
the secrecy performance degrades with an increasing number of eavesdroppers,
neither the asymptotic saturation value of the secrecy outage probability nor
the rate of improvement of the ESR with signal-to-noise-ratio depends on the
number of eavesdroppers
Optimal Friendly Jamming and Transmit Power Allocation in RIS-assisted Secure Communication
This paper analyzes the secrecy performance of a reconfigurable intelligent
surface (RIS) assisted wireless communication system with a friendly jammer in
the presence of an eavesdropper. The friendly jammer enhances the secrecy by
introducing artificial noise towards the eavesdropper without degrading the
reception at the destination. Approximate secrecy outage probability (SOP) is
derived in closed form. We also provide a simpler approximate closed-form
expression for the SOP in order to understand the effect of system parameters
on the performance and to find the optimal power allocation for the transmitter
and jammer. The optimal transmit and jamming power allocation factor is derived
by minimizing the SOP assuming a total power constraint. It is shown that the
SOP performance is significantly improved by the introduction of the jammer and
a gain of approximately dB is achieved at an SOP of by optimally
allocating power compared to the case of equal power allocation
Destination Scheduling for Secure Pinhole-Based Power-Line Communication
We propose an optimal destination scheduling scheme to improve the physical
layer security (PLS) of a power-line communication (PLC) based
Internet-of-Things system in the presence of an eavesdropper. We consider a
pinhole (PH) architecture for a multi-node PLC network to capture the keyhole
effect in PLC. The transmitter-to-PH link is shared between the destinations
and an eavesdropper which correlates all end-to-end links. The individual
channel gains are assumed to follow independent log-normal statistics.
Furthermore, the additive impulsive noise at each node is modeled by an
independent Bernoulli-Gaussian process. Exact computable expressions for the
average secrecy capacity (ASC) and the probability of intercept (POI)
performance over many different networks are derived. Approximate closed-form
expressions for the asymptotic ASC and POI are also provided. We find that the
asymptotic ASC saturates to a constant level as transmit power increases. We
observe that the PH has an adverse effect on the ASC. Although the shared link
affects the ASC, it has no effect on the POI. We show that by artificially
controlling the impulsive to background noise power ratio and its arrival rate
at the receivers, the secrecy performance can be improved