Survey on physical layer security for 5G wireless networks

Abstract Physical layer security is a promising approach that can benefit traditional encryption methods. The idea of physical layer security is to take advantage of the propagation medium’s features and impairments to ensure secure communication in the physical layer. This work introduces a comprehensive review of the main information-theoretic metrics used to measure the secrecy performance in physical layer security. Furthermore, a theoretical framework related to the most commonly used physical layer security techniques to improve secrecy performance is provided. Finally, our work surveys physical layer security research over several enabling 5G technologies, such as massive multiple-input multiple-output, millimeter-wave communications, heterogeneous networks, non-orthogonal multiple access, and full-duplex. We also include the key concepts of each of the technologies mentioned above. Also identified are future fields of research and technical challenges of physical layer security

On the secrecy performance over N-wave with diffuse power fading channel

Abstract We investigate the realistic propagation conditions effects on wireless physical layer security, which are different from classical Rice and Rayleigh fading. Specifically, we study how the superposition of a number of dominant specular waves and diffusely propagating components impacts the achievable secrecy performance. We derive analytical expressions for the secrecy outage probability and the average secrecy capacity, which have similar complexity to other alternatives in the literature derived for simpler fading models. We provide very useful insights on the impact on physical layer security of (i) the number; (ii) the relative amplitudes and (iii) the overall power of the dominant specular components. We show that it is possible to obtain remarkable improvements on the system secrecy performance when: (a) the relative amplitudes of the dominant specular components for the legitimate channel are more unbalanced compared to those of the eavesdropper’s channel, and (b) the power of the dominant components for the main channel is significantly larger than the power of the dominant components for the wiretap channel

Information-theoretic security of MIMO networks under kappa-mu shadowed fading channels

Abstract This paper investigates the impact of realistic propagation conditions on the achievable secrecy performance of multiple-input multiple-output systems in the presence of an eavesdropper (Eve). Specifically, we concentrate on the κ — μ shadowed fading model because its physical underpinnings capture a wide range of propagation conditions, while, at the same time, it allows for a much better tractability than other state-of-the-art fading models. By considering transmit antenna selection and maximal ratio combining reception at the legitimate (Bob) and Eve’s receiver sides, we study two relevant scenarios: 1) the transmitter knows Bob’s channel state information (CSI) but not Eve’s CSI, and 2) the transmitter is aware of the CSI of both Bob and Eve channels. For this purpose, we first obtain novel and tractable expressions for the statistics of the maximum of independent and identically distributed (i.i.d.) variates related to the legitimate channel. Based on these results, we derive novel closed-form expressions of the two aforementioned scenarios to assess the secrecy performance of the underlying system. Specifically, for cases: 1) the secrecy outage probability (SOP), the probability of strictly positive secrecy capacity (SPSC), and 2) the average secrecy capacity (ASC). Moreover, we develop analytical asymptotic expressions of the SOP and ASC in the high signal-to-noise ratio regime. In all instances, secrecy performance metrics are characterized in closed-form, without requiring the evaluation of Meijer-G or Fox-H functions. Some useful insights on how the different propagation conditions and the number of antennas impact the secrecy performance are also provided

On the statistics of the ratio of nonconstrained arbitrary α ‐ μ random variables:a general framework and applications

Abstract In this paper, we derive closed‐form exact expressions for the main statistics of the ratio of two squared α‐μ random variables, which are of interest in many scenarios for future wireless networks where generalized distributions are more suitable to fit with field data. Importantly, different from previous proposals, our expressions are general in the sense that are valid for nonconstrained arbitrary values of the parameters of the α‐μ distribution. Thus, the probability density function, cumulative distribution function, moment generating function, and higher‐order moments are given in terms of both (i) the Fox H‐function for which we provide a portable and efficient Wolfram Mathematica code and (ii) easily computable series expansions. Our expressions can be used straightforwardly in the performance analysis of a number of wireless communication systems, including either interference‐limited scenarios, spectrum sharing, full‐duplex, or physical‐layer security networks, for which we present the application of the proposed framework. Moreover, closed‐form expressions for some classical distributions, derived as special cases from the α‐μ distribution, are provided as byproducts. The validity of the proposed expressions is confirmed via Monte Carlo simulations