No full-text available
To read the full-text of this research,
you can request a copy directly from the authors.
Secrecy Performance Analysis of MIMO-V2V Communications With Keyhole Effect
... This fact spawned the development and application of physical layer (PHY) security, where the transmitter exploits secrecy channel coding to ensure perfect security, i.e., eavesdroppers cannot decipher confidential information from wiretapped messages [8]- [10]. A feasible method to further boost the secrecy performance at the PHY is to exploit the spatial degrees of freedom offered by multiple antennas [11]- [15]. Recently, secure beamforming design have attracted considerable research attention; see [16]- [19] and the references therein. ...
This work proposes a novel secure beamforming design for discrete lens array (DLA)-based continuous aperture phased (CAP) multiple-input multiple-output wiretap channels. The base station exploits a switching network to connect a subset of its analog beams or DLA feed antennas to the available radio frequency chains. The switching network and transmit beamformers are jointly designed to maximize the weighted secrecy sum-rate for this setting. The principal design problem reduces to an NP-hard mixed-integer non-linear programming. We invoke the fractional programming technique and the penalty dual decomposition method to develop a tractable iterative algorithm that effectively approximates the optimal design. Our numerical investigations validate the effectiveness of the proposed algorithm and its superior performance compared with the benchmark.
... Applying the Woodbury formula to (27) gives ...
The joint antenna selection and secure beamforming optimization problem is considered for a multi-antenna line-of-sight (LOS) wiretap channel. By utilizing the mathematical property of the optimal secure beamformer and physical property of the LOS channel, a branch-and-bound (BAB)-based method is proposed to achieve the optimal secrecy performance with a reduced time complexity than the brute-force search. To further improve the security-complexity trade-off, a greedy-based method is developed to achieve a close to optimal secrecy performance while involving much lower complexity than the BAB-based method. Numerical results confirm the effectiveness of the proposed methods compared to baseline schemes.
In this paper, the physical-layer security for a three-node wiretap system model is studied. Under the threat of multiple eavesdroppers, it is presumed that a transmitter is communicating with a legitimate receiver. The channels are assumed to be following cascaded κ-μ fading distributions. In addition, two scenarios for eavesdroppers’ interception and information-processing capabilities are investigated: colluding and non-colluding eavesdroppers. The positions of these eavesdroppers are assumed to be random in the non-colluding eavesdropping scenario, based on a homogeneous Poisson point process (HPPP). The security is examined in terms of the secrecy outage probability, the probability of non-zero secrecy capacity, and the intercept probability. The exact and asymptotic expressions for the secrecy outage probability and the probability of non-zero secrecy capacity are derived. The results demonstrate the effect of the cascade level on security. Additionally, the results indicate that as the number of eavesdroppers rises, the privacy of signals exchanged between legitimate ends deteriorates. Furthermore, in this paper, regarding the capabilities of tapping and processing the information, we provide a comparison between colluding and non-colluding eavesdropping.
The authors consider the secure transmission of information over power line communication (PLC) networks. The focus is on the secrecy guaranteed at the physical layer, named physical layer security (PLS). Although PLS has been deeply investigated for the wireless case, it is not the same for the PLC environment. Thus, starting from the knowledge in the wireless context, the authors extend the results to typical PLC scenarios. In particular, the PLC channel statistics is evaluated and a performance comparison among PLC and wireless channels is performed, in terms of secrecy rate distribution. For the PLC case, the secrecy rate distribution, under a total power constraint, is evaluated for both optimal and uniform power distributions in broadband channels. To provide experimental evidence, the authors consider channel measures obtained in an in-home measurement campaign. The underlying network presents a tree topology, which introduces frequency and spatial correlation among channels, and suffers from the keyhole effect, generated by branches that depart from the same node. As shown by the numerical results, these effects can reduce the secrecy rate. Finally, the authors evaluate the secrecy rate region for the multi-user broadcast channel considering both simulated channel realisations and experimental channel measures.
The capacity of the Gaussian wiretap channel model is analyzed when there are multiple antennas at the sender, intended receiver and eavesdropper. The associated channel matrices are fixed and known to all the terminals. A computable characterization of the secrecy capacity is established as the saddle point solution to a minimax problem. The converse is based on a Sato-type argument used in other broadcast settings, and the coding theorem is based on Gaussian wiretap codebooks. At high signal-to-noise ratio (SNR), the secrecy capacity is shown to be attained by simultaneously diagonalizing the channel matrices via the generalized singular value decomposition, and independently coding across the resulting parallel channels. The associated capacity is expressed in terms of the corresponding generalized singular values. It is shown that a semi-blind "masked" multi-input multi-output (MIMO) transmission strategy that sends information along directions in which there is gain to the intended receiver, and synthetic noise along directions in which there is not, can be arbitrarily far from capacity in this regime. Necessary and sufficient conditions for the secrecy capacity to be zero are provided, which simplify in the limit of many antennas when the entries of the channel matrices are independent and identically distributed. The resulting scaling laws establish that to prevent secure communication, the eavesdropper needs three times as many antennas as the sender and intended receiver have jointly, and that the optimum division of antennas between sender and intended receiver is in the ratio of 2:1.
The secrecy capacity of the multiple-antenna wiretap channel under the average total power constraint was recently characterized, independently, by Khisti and Wornell and Oggier and Hassibi using a Sato-like argument and matrix analysis tools. This paper presents an alternative characterization of the secrecy capacity of the multiple-antenna wiretap channel under a more general matrix constraint on the channel input using a channel-enhancement argument. This characterization is by nature information-theoretic and is directly built on the intuition regarding to the optimal transmission strategy in this communication scenario.
The proposed research performs the capacity analysis of the wireless channel described by the fluctuating double-Rayleigh with the line-of-sight model. The closed-form analytical expressions for the conditional capacity (in the case of arbitrary noninteger fading parameter) and the ergodic capacity (in the case of the integer fading parameter) are derived in terms of the extended generalized bivariate Meijer G-function. The exact solutions are succeeded by the approximating expressions deduced for the cases of small and large ratios between the Rician K-factor and the fading parameter. The performed numeric simulation verifies the correctness of the derived results and analyzes the proposed capacity approximation quality performance.
This letter studies the ergodic mutual information (EMI) of keyhole multiple-input multiple-output channels having finite-alphabet input signals. The EMI is first investigated for single-stream transmission considering both cases with and without the channel state information at the transmitter. Then, the derived results are extended to the scenario of multi-stream transmission. Asymptotic analyses are performed in the regime of high signal-to-noise ratio (SNR). The high-SNR EMI is shown to converge to a constant with its rate of convergence determined by the diversity order. On this basis, the influence of the keyhole effect on the EMI is discussed. The analytical results are validated by numerical simulations.
Vehicle-to-vehicle (V2V) communications under dense urban environments usually experience severe keyhole fading effect especially for multi-input multi-output (MIMO) channels, which degrades the capacity and outage performance due to the rank deficiency. To avoid these, the integration of MIMO and hybrid automatic repeat request (HARQ) is proposed to assist V2V communications in this paper. By using the methods of integral transforms, the outage probabilities are derived in closed-form for different HARQ-assisted schemes, including Type I-HARQ, HARQ with chase combining (HARQ-CC), and HARQ with incremental redundancy (HARQ-IR). With the results, meaningful insights are gained by conducting the asymptotic outage analysis. Specifically, it is revealed that full time diversity order can be achieved, while full spatial diversity order is unreachable as compared to MIMO-HARQ systems without keyhole effect. Moreover, we prove that the asymptotic outage probability is a monotonically increasing and convex function of the transmission rate. More importantly, although HARQ-IR performs better than HARQ-CC owing to its higher coding complexity, this advantage becomes negligible in the large-scale array regime. Finally, the numerical results are verified by Monte-Carlo simulations along with some in-depth discussions.
In this paper, physical-layer security (PLS) for an underlay cognitive radio network (CRN) over cascaded Rayleigh fading channels is studied. The underlying cognitive radio system consists of a secondary source transmitting to a destination over a cascaded Rayleigh fading channel. An eavesdropper is attempting to intercept the confidential information of the secondary users (SUs) pair. The secrecy is studied in terms of three main security metrics, which are the secrecy outage probability (SOP), the probability of non-zero secrecy capacity (P rnzc ), and the intercept probability (Pint). The effects of the path loss and the variation of the distances from the SU transmitter over the secrecy are also analyzed. Results reveal the great effect of the cascade level over the system secrecy. In addition, the effect of varying the interference threshold that the PU receiver can tolerate over the secrecy of the SUs pair is studied. The effect of the channel model parameters of both the main and the wiretap channels is investigated using both simulation and analytical results.
In this letter, we study the physical layer secrecy performance of the classic Wyner’s wiretap model over double Rayleigh fading channels for vehicular communications links. We derive novel and closed-form expressions for the average secrecy capacity (ASC) taking into account the effects of fading, path loss and eavesdropper location uncertainty. The asymptotic analysis for ASC is also conducted. The derived expressions can be used for secrecy capacity analysis of a number of scenarios including vehicular-to-vehicular (V2V) communications. The obtained results reveal the importance of taking the eavesdropper location uncertainty into consideration while designing V2V communication systems.
Linear algebra and matrix theory are fundamental tools in mathematical and physical science, as well as fertile fields for research. This second edition of this acclaimed text presents results of both classic and recent matrix analysis using canonical forms as a unifying theme and demonstrates their importance in a variety of applications. This thoroughly revised and updated second edition is a text for a second course on linear algebra and has more than 1,100 problems and exercises, new sections on the singular value and CS decompositions and the Weyr canonical form, expanded treatments of inverse problems and of block matrices, and much more.
It has well been established that multiple-input multiple-output (MIMO) transmission using multiple conductors can improve the data rate of power line communication (PLC) systems. In this paper, we investigate whether the presence of multiple conductors could also facilitate the communication of confidential messages by means of physical layer security methods. In particular, this paper focuses on the secrecy capacity of MIMO PLC. Numerical experiments show that multi-conductor PLC networks can enable a more secure communication compared to the single conductor case. On the other hand, we demonstrate that the keyhole property of PLC channels generally diminishes the secure communication capability compared to what would be achieved in a similar wireless communications setting.
This paper presents two general fading distributions, the kappa-mu distribution and the eta-mu distribution, for which fading models are proposed. These distributions are fully characterized in terms of measurable physical parameters. The kappa-mu distribution includes the Rice (Nakagami-n), the Nakagami-m, the Rayleigh, and the one-sided Gaussian distributions as special cases. The eta-mu distribution includes the Hoyt (Nakagami-q), the Nakagami-m, the Rayleigh, and the one-sided Gaussian distributions as special cases. Field measurement campaigns were used to validate these distributions. It was observed that their fit to experimental data outperformed that provided by the widely known fading distributions, such as the Rayleigh, Rice, and Nakagami-m. In particular, the kappa-mu distribution is better suited for line-of-sight applications, whereas the eta-mu distribution gives better results for non-line-of-sight applications.
This paper considers the transmission of confidential data over wireless channels. Based on an information-theoretic formulation of the problem, in which two legitimates partners communicate over a quasi-static fading channel and an eavesdropper observes their transmissions through a second independent quasi-static fading channel, the important role of fading is characterized in terms of average secure communication rates and outage probability. Based on the insights from this analysis, a practical secure communication protocol is developed, which uses a four-step procedure to ensure wireless information-theoretic security: (i) common randomness via opportunistic transmission, (ii) message reconciliation, (iii) common key generation via privacy amplification, and (iv) message protection with a secret key. A reconciliation procedure based on multilevel coding and optimized low-density parity-check (LDPC) codes is introduced, which allows to achieve communication rates close to the fundamental security limits in several relevant instances. Finally, a set of metrics for assessing average secure key generation rates is established, and it is shown that the protocol is effective in secure key renewal-even in the presence of imperfect channel state information.
On the ergodic mutual information of keyhole MIMO channels with finite inputs
- C Ouyang
- R R Müller
- Y Liu
- J Cheng
- H Yang
C. Ouyang, R. R. Müller, Y. Liu, J. Cheng, and H. Yang, "On the
ergodic mutual information of keyhole MIMO channels with finite
inputs," IEEE Commun. Lett., Accepted, Sep. 2022. [Online]. Available:
https://arxiv.org/abs/2112.04415