36,098 research outputs found
Wireless Physical Layer Security with Imperfect Channel State Information: A Survey
Physical layer security is an emerging technique to improve the wireless
communication security, which is widely regarded as a complement to
cryptographic technologies. To design physical layer security techniques under
practical scenarios, the uncertainty and imperfections in the channel knowledge
need to be taken into consideration. This paper provides a survey of recent
research and development in physical layer security considering the imperfect
channel state information (CSI) at communication nodes. We first present an
overview of the main information-theoretic measures of the secrecy performance
with imperfect CSI. Then, we describe several signal processing enhancements in
secure transmission designs, such as secure on-off transmission, beamforming
with artificial noise, and secure communication assisted by relay nodes or in
cognitive radio systems. The recent studies of physical layer security in
large-scale decentralized wireless networks are also summarized. Finally, the
open problems for the on-going and future research are discussed
Secure Transmission with Artificial Noise over Fading Channels: Achievable Rate and Optimal Power Allocation
We consider the problem of secure communication with multi-antenna
transmission in fading channels. The transmitter simultaneously transmits an
information bearing signal to the intended receiver and artificial noise to the
eavesdroppers. We obtain an analytical closed-form expression of an achievable
secrecy rate, and use it as the objective function to optimize the transmit
power allocation between the information signal and the artificial noise. Our
analytical and numerical results show that equal power allocation is a simple
yet near optimal strategy for the case of non-colluding eavesdroppers. When the
number of colluding eavesdroppers increases, more power should be used to
generate the artificial noise. We also provide an upper bound on the
signal-to-noise ratio (SNR) above which the achievable secrecy rate is positive
and show that the bound is tight at low SNR. Furthermore, we consider the
impact of imperfect channel state information (CSI) at both the transmitter and
the receiver and find that it is wise to create more artificial noise to
confuse the eavesdroppers than to increase the signal strength for the intended
receiver if the CSI is not accurately obtained.Comment: To appear in IEEE Transactions on Vehicular Technolog
On the Monetary Loss Due to Passive and Active Attacks on MIMO Smart Grid Communications
We consider multiple source nodes (consumers) communicating wirelessly their
energy demands to the meter data-management system (MDMS) over the subarea
gateway(s). We quantify the impacts of passive and active security attacks on
the wireless communications system's reliability and security as well as the
energy-demand estimation-error cost in dollars paid by the utility. We adopt a
multiple-input multiple-output multi-antenna-eavesdropper (MIMOME) wiretap
channel model. To secure the MIMO wireless communication system, the legitimate
nodes generate artificial noise (AN) vectors to mitigate the effect of the
passive eavesdropping attacks. In addition, we propose a redundant design where
multiple gateways are assumed to coexist in each subarea to forward the
consumers' energy-demand messages. We quantify the redundant designs impact on
the communication reliability between the consumers and the MDMS and on the
energy-demand estimation-error cost
Optimal Power Allocation for Artificial Noise under Imperfect CSI against Spatially Random Eavesdroppers
In this correspondence, we study the secure multiantenna transmission with
artificial noise (AN) under imperfect channel state information in the presence
of spatially randomly distributed eavesdroppers. We derive the optimal
solutions of the power allocation between the information signal and the AN for
minimizing the secrecy outage probability (SOP) under a target secrecy rate and
for maximizing the secrecy rate under a SOP constraint, respectively. Moreover,
we provide an interesting insight that channel estimation error affects the
optimal power allocation strategy in opposite ways for the above two
objectives. When the estimation error increases, more power should be allocated
to the information signal if we aim to decrease the rate-constrained SOP,
whereas more power should be allocated to the AN if we aim to increase the
SOP-constrained secrecy rate.Comment: 7 pages, 6 figure
Secure Directional Modulation to Enhance Physical Layer Security in IoT Networks
In this work, an adaptive and robust null-space projection (AR-NSP) scheme is
proposed for secure transmission with artificial noise (AN)-aided directional
modulation (DM) in wireless networks. The proposed scheme is carried out in
three steps. Firstly, the directions of arrival (DOAs) of the signals from the
desired user and eavesdropper are estimated by the Root Multiple Signal
Classificaiton (Root-MUSIC) algorithm and the related signal-to-noise ratios
(SNRs) are estimated based on the ratio of the corresponding eigenvalue to the
minimum eigenvalue of the covariance matrix of the received signals. In the
second step, the value intervals of DOA estimation errors are predicted based
on the DOA and SNR estimations. Finally, a robust NSP beamforming DM system is
designed according to the afore-obtained estimations and predictions. Our
examination shows that the proposed scheme can significantly outperform the
conventional non-adaptive robust scheme and non-robust NSP scheme in terms of
achieving a much lower bit error rate (BER) at the desired user and a much
higher secrecy rate (SR). In addition, the BER and SR performance gains
achieved by the proposed scheme relative to other schemes increase with the
value range of DOA estimation error.Comment: 9 pages, 12 figures, Io
Secure Massive MIMO Transmission with an Active Eavesdropper
In this paper, we investigate secure and reliable transmission strategies for
multi-cell multi-user massive multiple-input multiple-output (MIMO) systems
with a multi-antenna active eavesdropper. We consider a time-division duplex
system where uplink training is required and an active eavesdropper can attack
the training phase to cause pilot contamination at the transmitter. This forces
the precoder used in the subsequent downlink transmission phase to implicitly
beamform towards the eavesdropper, thus increasing its received signal power.
Assuming matched filter precoding and artificial noise (AN) generation at the
transmitter, we derive an asymptotic achievable secrecy rate when the number of
transmit antennas approaches infinity. For the case of a single-antenna active
eavesdropper, we obtain a closed-form expression for the optimal power
allocation policy for the transmit signal and the AN, and find the minimum
transmit power required to ensure reliable secure communication. Furthermore,
we show that the transmit antenna correlation diversity of the intended users
and the eavesdropper can be exploited in order to improve the secrecy rate. In
fact, under certain orthogonality conditions of the channel covariance
matrices, the secrecy rate loss introduced by the eavesdropper can be
completely mitigated.Comment: Accepted by IEEE Transactions on Information Theory. arXiv admin
note: text overlap with arXiv:1505.0123
A Survey on MIMO Transmission with Discrete Input Signals: Technical Challenges, Advances, and Future Trends
Multiple antennas have been exploited for spatial multiplexing and diversity
transmission in a wide range of communication applications. However, most of
the advances in the design of high speed wireless multiple-input multiple
output (MIMO) systems are based on information-theoretic principles that
demonstrate how to efficiently transmit signals conforming to Gaussian
distribution. Although the Gaussian signal is capacity-achieving, signals
conforming to discrete constellations are transmitted in practical
communication systems. As a result, this paper is motivated to provide a
comprehensive overview on MIMO transmission design with discrete input signals.
We first summarize the existing fundamental results for MIMO systems with
discrete input signals. Then, focusing on the basic point-to-point MIMO
systems, we examine transmission schemes based on three most important criteria
for communication systems: the mutual information driven designs, the mean
square error driven designs, and the diversity driven designs. Particularly, a
unified framework which designs low complexity transmission schemes applicable
to massive MIMO systems in upcoming 5G wireless networks is provided in the
first time. Moreover, adaptive transmission designs which switch among these
criteria based on the channel conditions to formulate the best transmission
strategy are discussed. Then, we provide a survey of the transmission designs
with discrete input signals for multiuser MIMO scenarios, including MIMO uplink
transmission, MIMO downlink transmission, MIMO interference channel, and MIMO
wiretap channel. Additionally, we discuss the transmission designs with
discrete input signals for other systems using MIMO technology. Finally,
technical challenges which remain unresolved at the time of writing are
summarized and the future trends of transmission designs with discrete input
signals are addressed.Comment: 110 pages, 512 references, submit to Proceedings of the IEE
Data-Aided Secure Massive MIMO Transmission under the Pilot Contamination Attack
In this paper, we study the design of secure communication for time division
duplex multi-cell multi-user massive multiple-input multiple-output (MIMO)
systems with active eavesdropping. We assume that the eavesdropper actively
attacks the uplink pilot transmission and the uplink data transmission before
eavesdropping the downlink data transmission of the users. We exploit both the
received pilots and the received data signals for uplink channel estimation. We
show analytically that when the number of transmit antennas and the length of
the data vector both tend to infinity, the signals of the desired user and the
eavesdropper lie in different eigenspaces of the received signal matrix at the
base station provided that their signal powers are different. This finding
reveals that decreasing (instead of increasing) the desired user's signal power
might be an effective approach to combat a strong active attack from an
eavesdropper. Inspired by this observation, we propose a data-aided secure
downlink transmission scheme and derive an asymptotic achievable secrecy
sum-rate expression for the proposed design. For the special case of a
single-cell single-user system with independent and identically distributed
fading, the obtained expression reveals that the secrecy rate scales
logarithmically with the number of transmit antennas. This is the same scaling
law as for the achievable rate of a single-user massive MIMO system in the
absence of eavesdroppers. Numerical results indicate that the proposed scheme
achieves significant secrecy rate gains compared to alternative approaches
based on matched filter precoding with artificial noise generation and null
space transmission.Comment: To appear in IEEE Transactions on Communications. arXiv admin note:
substantial text overlap with arXiv:1801.0707
Power-Efficient and Secure WPCNs with Hardware Impairments and Non-Linear EH Circuit
In this paper, we design a robust resource allocation algorithm for a
wireless-powered communication network (WPCN) taking into account residual
hardware impairments (HWIs) at the transceivers, the imperfectness of the
channel state information, and the non-linearity of practical radio frequency
energy harvesting circuits. In order to ensure power-efficient secure
communication, physical layer security techniques are exploited to deliberately
degrade the channel quality of a multiple-antenna eavesdropper. The resource
allocation algorithm design is formulated as a non-convex optimization problem
for minimization of the total consumed power in the network, while guaranteeing
the quality of service of the information receivers in terms of secrecy rate.
The globally optimal solution of the optimization problem is obtained via a
two-dimensional search and semidefinite programming relaxation. To strike a
balance between computational complexity and system performance, a
low-complexity iterative suboptimal resource allocation algorithm is then
proposed.
Numerical results demonstrate that both the proposed optimal and suboptimal
schemes can significantly reduce the total system power consumption required
for guaranteeing secure communication, and unveil the impact of HWIs on the
system performance: (1) residual HWIs create a system performance bottleneck in
the high transmit/receive power regimes; (2) increasing the number of transmit
antennas can effectively reduce the system power consumption and alleviate the
performance degradation due to residual HWIs; (3) imperfect CSI increases the
system power consumption and exacerbates the impact of residual HWIs.Comment: Submitted for possible journal publicatio
Multi-Objective Optimization for Robust Power Efficient and Secure Full-Duplex Wireless Communication Systems
In this paper, we investigate the power efficient resource allocation
algorithm design for secure multiuser wireless communication systems employing
a full-duplex (FD) base station (BS) for serving multiple half-duplex (HD)
downlink (DL) and uplink (UL) users simultaneously. We propose a
multi-objective optimization framework to study two conflicting yet desirable
design objectives, i.e., total DL transmit power minimization and total UL
transmit power minimization. To this end, the weighed Tchebycheff method is
adopted to formulate the resource allocation algorithm design as a
multi-objective optimization problem (MOOP). The considered MOOP takes into
account the quality-of-service (QoS) requirements of all legitimate users for
guaranteeing secure DL and UL transmission in the presence of potential
eavesdroppers. Thereby, secure UL transmission is enabled by the FD BS and
would not be possible with an HD BS. The imperfectness of the channel state
information of the eavesdropping channels and the inter-user interference
channels is incorporated for robust resource allocation algorithm design.
Although the considered MOOP is non-convex, we solve it optimally by
semidefinite programming (SDP) relaxation. Simulation results not only unveil
the trade-off between the total DL transmit power and the total UL transmit
power, but also confirm the robustness of the proposed algorithm against
potential eavesdroppers.Comment: Submitted for possible journal publicatio
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