11,507 research outputs found
Physical Layer Security of Generalised Pre-coded Spatial Modulation with Antenna Scrambling
We now advocate a novel physical layer security solution that is unique to
our previously proposed GPSM scheme with the aid of the proposed antenna
scrambling. The novelty and contribution of our paper lies in three aspects: 1/
principle: we introduce a `security key' generated at Alice that is unknown to
both Bob and Eve, where the design goal is that the publicly unknown security
key only imposes barrier for Eve. 2/ approach: we achieve it by conveying
useful information only through the activation of RA indices, which is in turn
concealed by the unknown security key in terms of the randomly scrambled
symbols used in place of the conventional modulated symbols in GPSM scheme. 3/
design: we consider both Circular Antenna Scrambling (CAS) and Gaussian Antenna
Scrambling (GAS) in detail and the resultant security capacity of both designs
are quantified and compared
Two High-Performance Amplitude Beamforming Schemes for Secure Precise Communication and Jamming with Phase Alignment
To severely weaken the eavesdropper's ability to intercept confidential
message (CM), a precise jamming (PJ) idea is proposed by making use of the
concept of secure precise wireless transmission (SPWT). Its basic idea is to
focus the transmit energy of artificial noise (AN) onto the neighborhood of
eavesdropper (Eve) by using random subcarrier selection (RSS), directional
modulation, phase alignment (PA), and amplitude beamforming (AB). By doing so,
Eve will be seriously interfered with AN. Here, the conventional joint
optimization of phase and amplitude is converted into two independent phase and
amplitude optimization problems. Considering PJ and SPWT require PA, the joint
optimization problem reduces to an amplitude optimization problem. Then, two
efficient AB schemes are proposed: leakage and maximizing receive
power(Max-RP). With existing equal AB (EAB) as a performance reference,
simulation results show that the proposed Max-RP and leakage AB methods perform
much better than conventional method in terms of both bit-error-rate (BER) and
secrecy rate (SR) at medium and high signal-to-noise ratio regions. The
performance difference between the two proposed leakage and Max-RP amplitude
beamformers is trivial. Additionally, we also find the fact that all three AB
schemes EA, Max-RP, and leakage can form two main peaks of AN and CM around Eve
and the desired receiver (Bob), respectively. This is what we call PJ and SPWT
Two High-performance Schemes of Transmit Antenna Selection for Secure Spatial Modulation
In this paper, a secure spatial modulation (SM) system with artificial noise
(AN)-aided is investigated. To achieve higher secrecy rate (SR) in such a
system, two high-performance schemes of transmit antenna selection (TAS),
leakage-based and maximum secrecy rate (Max-SR), are proposed and a generalized
Euclidean distance-optimized antenna selection (EDAS) method is designed. From
simulation results and analysis, the four TAS schemes have an decreasing order:
Max-SR, leakage-based, generalized EDAS, and random (conventional), in terms of
SR performance. However, the proposed Max-SR method requires the exhaustive
search to achieve the optimal SR performance, thus its complexity is extremely
high as the number of antennas tends to medium and large scale. The proposed
leakage-based method approaches the Max-SR method with much lower complexity.
Thus, it achieves a good balance between complexity and SR performance. In
terms of bit error rate (BER), their performances are in an increasing order:
random, leakage-based, Max-SR, and generalized EDAS
Low-Complexity Linear Precoding for Secure Spatial Modulation
In this work, we investigate linear precoding for secure spatial modulation.
With secure spatial modulation, the achievable secrecy rate does not have an
easy-to-compute mathematical expression, and hence, has to be evaluated
numerically, which leads to high complexity in the optimal precoder design. To
address this issue, an accurate and analytical approximation of the secrecy
rate is derived in this work. Using this approximation as the objective
function, two low-complexity linear precoding methods based on gradient descend
(GD) and successive convex approximation (SCA) are proposed. The GD-based
method has much lower complexity but usually converges to a local optimum. On
the other hand, the SCA-based method uses semi-definite relaxation to deal with
the non-convexity in the precoder optimization problem and achieves
near-optimal solution. Compared with the existing GD-based precoder design in
the literature that directly uses the exact and numerically evaluated secrecy
capacity as the objective function, the two proposed designs have significantly
lower complexity. Our SCA-based design even achieves a higher secrecy rate than
the existing GD-based design.Comment: 11pages, 8figure
Imbalanced Beamforming by a Multi-antenna Source for Secure Utilization of an Untrusted Relay
We investigate a relay network where a multiantenna source can potentially
utilize an unauthenticated (untrusted) relay to augment its direct transmission
of a confidential message to the destination. Since the relay is untrusted, it
is desirable to protect the confidential data from it while simultaneously
making use of it to increase the reliability of the transmission. We present a
low-complexity scheme denoted as imbalanced beamforming based on linear
beamforming and constellation mapping that ensures perfect physical-layer
security even while utilizing the untrusted relay. Furthermore, the security of
the scheme holds even if the relay adopts the conventional decodeand- forward
protocol, unlike prior work. Simulation results show that the proposed
imbalanced signaling maintains a constant BER of 0.5 at the eavesdropper at any
SNR and number of source antennas, while maintaining or improving the detection
performance of the destination compared to not utilizing the relay or existing
security methods.Comment: To appear, IEEE Communications Letters, 201
Directional Modulation: A Secure Solution to 5G and Beyond Mobile Networks
Directional modulation (DM), as an efficient secure transmission way, offers
security through its directive property and is suitable for line-of-propagation
(LoP) channels such as millimeter wave (mmWave) massive multiple-input
multiple-output (MIMO), satellite communication, unmanned aerial vehicle (UAV),
and smart transportation. If the direction angle of the desired received is
known, the desired channel gain vector is obtainable. Thus, in advance, the DM
transmitter knows the values of directional angles of desired user and
eavesdropper, or their direction of arrival (DOAs) because the beamforming
vector of confidential messages and artificial noise (AN) projection matrix is
mainly determined by directional angles of desired user and eavesdropper. For a
DM transceiver, working as a receiver, the first step is to measure the DOAs of
desired user and eavesdropper. Then, in the second step, using the measured
DOAs, the beamforming vector of confidential messages and AN projection matrix
is designed. In this paper, we describe the DOA measurement methods, power
allocation, and beamforming in DM networks. A machine learning-based DOA
measurement method is proposed to make a substantial SR performance gain
compared to single-snapshot measurement without machine learning for a given
null-space projection beamforming scheme. However, for a conventional DM
network, there still exists a serious secure issue: the eavesdropper moves
inside the main beam of the desired user and may intercept the confidential
messages intended to the desired users because the beamforming vector of
confidential messages and AN projection matrix are only angle-dependence. To
address this problem, we present a new concept of secure and precise
transmission, where the transmit waveform has two-dimensional even
three-dimensional dependence by using DM, random frequency selection, and phase
alignment at DM transmitter
Symbol-level and Multicast Precoding for Multiuser Multiantenna Downlink: A Survey, Classification and Challenges
Precoding has been conventionally considered as an effective means of
mitigating the interference and efficiently exploiting the available in the
multiantenna downlink channel, where multiple users are simultaneously served
with independent information over the same channel resources. The early works
in this area were focused on transmitting an individual information stream to
each user by constructing weighted linear combinations of symbol blocks
(codewords). However, more recent works have moved beyond this traditional view
by: i) transmitting distinct data streams to groups of users and ii) applying
precoding on a symbol-per-symbol basis. In this context, the current survey
presents a unified view and classification of precoding techniques with respect
to two main axes: i) the switching rate of the precoding weights, leading to
the classes of block- and symbol-level precoding, ii) the number of users that
each stream is addressed to, hence unicast-/multicast-/broadcast- precoding.
Furthermore, the classified techniques are compared through representative
numerical results to demonstrate their relative performance and uncover
fundamental insights. Finally, a list of open theoretical problems and
practical challenges are presented to inspire further research in this area.Comment: Submitted to IEEE Communications Surveys & Tutorial
Secure Transmission with Large Numbers of Antennas and Finite Alphabet Inputs
In this paper, we investigate secure transmission over the large-scale
multiple-antenna wiretap channel with finite alphabet inputs. First, we
investigate the case where instantaneous channel state information (CSI) of the
eavesdropper is known at the transmitter. We show analytically that a
generalized singular value decomposition (GSVD) based design, which is optimal
for Gaussian inputs, may exhibit a severe performance loss for finite alphabet
inputs in the high signal-to-noise ratio (SNR) regime. In light of this, we
propose a novel Per-Group-GSVD (PG-GSVD) design which can effectively
compensate the performance loss caused by the GSVD design. More importantly,
the computational complexity of the PG-GSVD design is by orders of magnitude
lower than that of the existing design for finite alphabet inputs in [1] while
the resulting performance loss is minimal. Then, we extend the PG-GSVD design
to the case where only statistical CSI of the eavesdropper is available at the
transmitter. Numerical results indicate that the proposed PG-GSVD design can be
efficiently implemented in large-scale multiple-antenna systems and achieves
significant performance gains compared to the GSVD design.Comment: Accepted by IEEE Transactions on Communications. arXiv admin note:
text overlap with arXiv:1612.0832
Regional Robust Secure Precise Wireless Transmission Design for Multi-user UAV Broadcasting System
In this paper, two regional robust secure precise wireless transmission
(SPWT) schemes for multi-user unmanned aerial vehicle (UAV) :1) regional
signal-to-leakage-and-noise ratio (SLNR) and
artificial-noise-to-leakage-and-noise ratio (ANLNR) (R-SLNR-ANLNR) maximization
and 2) point SLNR and ANLNR (P-SLNR-ANLNR) maximization, are proposed to tackle
with the estimation errors of the target users' location. In SPWT system, the
estimation error for SPWT can not be ignored. However the conventional robust
methods in secure wireless communications optimize the beamforming vector in
the desired positions only in statistical means and can not guarantee the
security for each symbol. Proposed regional robust schemes are designed for
optimizing the secrecy performance in the whole error region around the
estimated location. Specifically, with known maximal estimation error, we
define target region and wiretap region. Then design an optimal beamforming
vector and an artificial noise projection matrix, which achieve the
confidential signal in the target area having the maximal power while only few
signal power is conserved in the potential wiretap region. Instead of
considering the statistical distributions of the estimated errors into
optimization, we optimize the SLNR and ANLNR of the whole target area, which
significantly decreases the complexity. Moreover, the proposed schemes can
ensure that the desired users are located in the optimized region, which are
more practical than conventional methods. Simulation results show that our
proposed regional robust SPWT design is capable of substantially improving the
secrecy rate compared to the conventional non-robust method. The P-SLNR-ANLNR
maximization-based method has the comparable secrecy performance with a lower
complexity than that of the R-SLNR-ANLNR maximization-based method
Physical Layer Security for RF Satellite Channels in the Finite-length Regime
Secure communications is becoming increasingly relevant in the development of
space technology. Well established cryptographic technology is already in place
and is expected to continue to be so. On the other hand, information
theoretical security emerges as a post-quantum versatile candidate to
complement overall security strength. In order to prove such potential,
performance analysis methods are needed that consider realistic legitimate and
eavesdropper system assumptions and non-asymptotic coding lengths. In this
paper we propose the design of secure radio frequency (RF) satellite links with
realistic system assumptions. Our contribution is three-fold. First, we propose
a wiretap channel model for the finite-length regime. The model includes an
stochastic wiretap encoding method using existing practical linear error
correcting codes and hash codes. Secrecy is provided with privacy
amplification, for which the finite-length secrecy metric is given that upper
bounds semantic secrecy. Second, we derive a novel RF (broadcast) satellite
wiretap channel model that parameterizes the stochastic degraded channel around
the legitimate channel, a necessary condition to enable secure communication.
Finally, we show the design of a secure satellite physical layer and
finite-length performance evaluation. In doing so, we define as sacrifice rate
the fixed fraction of the overall coding rate budget for reliability that needs
to be allocated to secrecy. Our methodology does not make use of channel side
information of the eavesdropper, only assumes worst case system assumptions. We
illustrate our proposed design method with numerical results using practical
error correcting codes in current standards of satellite communication.Comment: Submitted to IEEE journal Corrected typo in eq. (18) and its
derivation eq. (46). arXiv admin note: text overlap with arXiv:1610.0725
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