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Showing papers on "Fading distribution published in 2019"


Journal ArticleDOI
TL;DR: The physical layer secrecy performance of a hybrid satellite and free-space optical (FSO) cooperative system is studied and it is found that with the AF with fixed gain scheme, the secrecy diversity order of the investigated system is only dependent on the channel characteristics of the FSO link and theFSO detection type, whereas the secrecy Diversity is zero when the relay node employs DF or AF with variable-gain schemes.
Abstract: In this paper, we study the physical layer secrecy performance of a hybrid satellite and free-space optical (FSO) cooperative system. The satellite links are assumed to follow the shadowed-Rician fading distribution, and the channel of the terrestrial link between the relay and destination is assumed to experience the gamma-gamma fading. For the FSO communications, the effects of different types of detection techniques (i.e., heterodyne detection and intensity modulation with direct detection) as well as the pointing error are considered. We derive exact analytical expressions for the average secrecy capacity and secrecy outage probability (SOP) for both cases of amplify-and-forward (AF) and decode-and-forward (DF) relaying. The asymptotic analysis for the SOP is also conducted to provide more insights on the impact of FSO and satellite channels on secrecy performance. It is found that with the AF with fixed gain scheme, the secrecy diversity order of the investigated system is only dependent on the channel characteristics of the FSO link and the FSO detection type, whereas the secrecy diversity is zero when the relay node employs DF or AF with variable-gain schemes.

104 citations


Journal ArticleDOI
TL;DR: A modeling approach from robust control to wireless communication is brought—the wireless channel characteristics are given a nominal model around which to allow for some quantified uncertainty, and certain key URLLC-relevant parameters are proposed along which the model uncertainty is to be bounded.
Abstract: Interactive, immersive, and other timing-critical applications demand ultra-reliable low-latency communication (URLLC). To build wireless communication systems that can support these applications, understanding the relevant characteristics of the wireless medium is paramount. Although wireless channel characteristics and dynamics have been extensively studied, it is important to revisit these concepts in the context of the strict demands of low-latency and ultra-high reliability. In this paper, we bring a modeling approach from robust control to wireless communication—the wireless channel characteristics are given a nominal model around which we allow for some quantified uncertainty. We propose certain key URLLC-relevant parameters along which the model uncertainty is to be bounded. To validate the nominal model of the spatially independent quasi-static Rayleigh fading, we take an in-depth look at the spatial and temporal correlations based on Jakes’ model. We find that although the Rayleigh fading process is band-limited, the quasi-static assumption is not safe for relay selection even well within a single coherence time. We also find that under reasonable conditions, the spatial correlation of channels provide a fading distribution that is not too far off from an independent spatial fading model. In addition, we look at the impact of these channel models on cooperative communication-based systems. We find that while spatial-diversity-based techniques are necessary to combat the adverse effects of fading, time-diversity-based techniques are necessary to be robust against unmodeled errors. Robust URLLC systems need to operate with both an adequate SNR margin and a time margin through repetitions.

30 citations


Journal ArticleDOI
TL;DR: The results presented show that hybrid system can overcome the weakness of FSO links which are susceptible to atmospheric turbulence and pointing errors and prove the accuracy of the derived expressions.

27 citations


Journal ArticleDOI
TL;DR: Novel expression of the end-to-end cumulative distribution function (CDF) for the proposed mixed RF/FSO system has been derived and utilized to obtain the closed-form expression for outage probability and bit-error-rate of the overall system.

23 citations


Journal ArticleDOI
TL;DR: This paper presents performance analysis for two cooperative amplify-and-forward (AF) relaying systems in which hybrid combinations of radio frequency and free space optics links have been considered, where the receiver employs the selection combining method.

18 citations


Journal ArticleDOI
TL;DR: This letter provides an interference functional and Laplace transform based analysis using stochastic geometry to evaluate the expectation over the interference, which is further used to derive the coverage probability expressions for device-to-device (D2D) links.
Abstract: In this letter, we provide an interference functional and Laplace transform based analysis using stochastic geometry to evaluate the expectation over the interference, which is further used to derive the coverage probability expressions for device-to-device (D2D) links. We assume a more practically relevant Nakagami- $ {m}$ fading distribution to model fading between the D2D communication links considering interference from both D2D and cellular links. We also derive a bound on the coverage probability, which simplifies the coverage computations at higher values of the fading parameter. Furthermore, the numerical results corroborate the presented coverage analysis.

16 citations


Journal ArticleDOI
TL;DR: An approach to remove the effect of fading on deterministic part of the large-scale model and verify its accuracy using a single transmitter-receiver scenario and validate its precision by Kolmogorov–Smirnov(K–S) goodness-of-fit test is proposed.
Abstract: Channel modeling is essential for design and performance evaluation of numerous protocols in vehicular networks. In this paper, we study and provide results for large- and small-scale modeling of communication channel in dense vehicular networks. We first propose an approach to remove the effect of fading on deterministic part of the large-scale model and verify its accuracy using a single transmitter-receiver scenario. Two-ray model is then utilized for path-loss characterization and its parameters are derived from the empirical data based on a newly proposed method. Afterward, we use α -μ distribution to model the fading behavior of vehicular networks for the first time, and validate its precision by Kolmogorov-Smirnov(K-S) goodness-of-fit test. To this end, the significantly better performance of utilizing α - μ distribution over the most adopted fading distribution in the vehicular channels literature, i.e., Nakagami-m, in terms of passing K-S test has been investigated and statistically verified in this paper. A large received signal strength indicator (RSSI) data set from a measurement campaign is used to evaluate our claims. Moreover, the whole model is implemented in a reliable discrete event network simulator which is widely used in the academic and industrial research for network analysis, i.e., network simulator-3 (ns-3), to show the outcome of the proposed model in the presence of upper layer network protocols.

14 citations


Journal ArticleDOI
TL;DR: The results demonstrate that the asymptotic notions of outage probability and outage capacity are in fact reasonable criteria even in the finite blocklength regime.
Abstract: We consider the lossy transmission of a single source over parallel additive white Gaussian noise channels with independent quasi-static fading, which we term the lossy multi-connectivity problem. We assume that only the decoder has access to the channel state information. Motivated by ultra-reliable and low latency communication requirements, we are interested in the finite blocklength performance of the problem, i.e., the minimal excess-distortion probability of transmitting $k$ source symbols over $n$ channel uses. By generalizing non-asymptotic bounds by Kostina and Verdu for the lossy joint source-channel coding problem, we derive non-asymptotic achievability and converse bounds for the lossy multi-connectivity problem. Using these non-asymptotic bounds and under mild conditions on the fading distribution, we derive approximations for the finite blocklength performance in the spirit of second-order asymptotics for any discrete memoryless source under an arbitrary bounded distortion measure. Furthermore, in the achievability part, we analyze the performance of a universal coding scheme by modifying the universal joint source-channel coding scheme by Csiszar and using a generalized minimum distance decoder. Our results demonstrate that the asymptotic notions of outage probability and outage capacity are in fact reasonable criteria even in the finite blocklength regime. Finally, we illustrate our results via numerical examples.

13 citations


Journal ArticleDOI
TL;DR: The channel capacity examinations analyzed in this paper depend on the Oceanic turbulence parameters, especially for the anisotropic factor of oceanic turbulence, and also depends on the other system parameters such as wavelength, link distance, noise variance, and the quantum efficiency of the photodetector.
Abstract: The effect of anisotropy on the channel capacity of underwater optical wireless communication (OWC) links operating in strong oceanic turbulence is investigated. We consider a Gaussian beam wave propagating through a turbulent oceanic fading channel whose statistical distribution is modelled by a gamma-gamma function. To numerically calculate the channel capacity of the OWC system, related entities of the propagating beam such as coherence length, received signal intensity, and the scintillation index are formulated. Further, in this way, the received signal-to-noise ratio and fading distribution of the channel are obtained. The channel capacity examinations analyzed in this paper depend on the oceanic turbulence parameters, especially for the anisotropic factor of oceanic turbulence, and also depend on the other system parameters such as wavelength, link distance, noise variance, and the quantum efficiency of the photodetector.

11 citations


Journal ArticleDOI
TL;DR: A moment generating function (MGF) based mathematical expression is derived to compute bit error rate (BER) for spatial modulation (SM) system over generalized α − κ − μ fading channel distribution.

8 citations


Journal ArticleDOI
TL;DR: Two schemes for the system performance improvement in the higher data rate and long length terrestrial free-space optical (FSO) links are proposed and closed-form expressions for the probability of fade for each are derived.

Proceedings ArticleDOI
14 Jul 2019
TL;DR: The Akaike information criterion (AIC), which aims to solve the problem of the optimal model selection, is used to select the best fading distribution for vehicle radio channel from Rayleigh and Rician distributions in a highway environment.
Abstract: Small scale characteristics are very important for the vehicle-to-vehicle (V2V) radio channel. In this paper, the Akaike information criterion (AIC), which aims to solve the problem of the optimal model selection, is used to select the best fading distribution for vehicle radio channel from Rayleigh and Rician distributions in a highway environment. The measurement results show that the Rician distribution has the best fitting for the V2V radio channel in a highway communication environment. Influence from surroundings on the small scale characteristics are analyzed. The Rician K-factors are extracted and modeled based on the measurement data. It can be found that the mean value of Rician K-factor is around 4.86 dB in this scenario.

Journal ArticleDOI
TL;DR: This paper analyzes the performance of quadrature spatial modulation (QSM) multiple-input multiple-output (MIMO) system in cooperative decode and forward (DF) networks over correlated and imperfect η–$$\mu $$μ fading channels.
Abstract: This paper analyzes the performance of quadrature spatial modulation (QSM) multiple-input multiple-output (MIMO) system in cooperative decode and forward (DF) networks over correlated and imperfect $$\eta $$ – $$\mu $$ fading channels. QSM is a recently proposed propitious MIMO technique that promises significant advantages over conventional MIMO schemes including high spectral efficiency with single RF-chain transmitter and very low receiver complexity. In this study, DF cooperative communication system adopting QSM technique is presented and throughly analyzed. Single or multiple DF relays are placed between the source and the destination to cooperate in the transmission process. Only the relays that decode the signal correctly will participate in the retransmission process. The end to end performance of the considered system is analyzed over correlated and imperfect $$\eta $$ – $$\mu $$ fading channels. The $$\eta $$ – $$\mu $$ channel is a general fading distribution that includes some other well-known channels, such as Rayleigh and Nakagami-m, as spacial cases. Monte Carlo simulation results are presented to corroborate the accuracy of the conducted analysis. The impact of spatial correlation, imperfect channel estimation and the fading parameters $$\eta $$ and $$\mu $$ on the overall performance is investigated and exhaustively discussed.

Journal ArticleDOI
TL;DR: A new method for the estimation of the α-μ coefficients based on theα-μ autocorrelation function is proposed, validated using field data and comparing the results from empirical autoc orrelation function with the results obtained from the moment-based estimator.

Proceedings ArticleDOI
01 Apr 2019
TL;DR: In this article, the closed form expression for the exact average symbol error rate (ASER) was derived for a selective decode-and-forward (DF) relay system with multiple receive antennas at the relay and the destination node.
Abstract: In this paper, we analyze a M-ary quadrature amplitude modulation (M-QAM) scheme over twowave with diffuse power (TWDP) fading environment for multiple receive antennas based system. We consider a Selective decode-and-forward (DF) relayed system with multiple receive antennas at the relay and the destination node. Utilizing the moment generating function of TWDP fading distribution, we derive the closed form expression for the exact average symbol error rate (ASER) for MQAM scheme. Moreover, in order to get the better insight of the system, we also perform the asymptotic analysis for the considered system. Simulation results are presented for different scenarios and it is observed that analytical results show excellent agreement with the simulation results.


Proceedings ArticleDOI
26 Dec 2019
TL;DR: In this article, the security over κ-µ fading distribution is analyzed to identify the multipath fading distributions that can be constituted from this fading model for security purposes, and the closed-form analytical expressions of security performance parameters such as probability of nonzero secrecy capacity (PNSC), secure outage probability (SOP), and the ergodic secrecy capacity(ESC) have been derived to get a proper insight of the effect of κµ ε fading parameters.
Abstract: The security over κ–µ fading distribution is analyzed in this paper to identify the multipath fading distributions that can be constituted from this fading model for security purposes. The closed-form analytical expressions (CFAEs) of security performance parameters such as probability of non-zero secrecy capacity (PNSC), secure outage probability (SOP) and the ergodic secrecy capacity (ESC) have been derived to get a proper insight of the effect of κ–µ fading parameters. Our results prove that the security performance of κ–µ fading channel includes the security performance of one sided Gaussian, Nakagami-m, Rician and Rayleigh fading channels. Finally, analytical results are tested by Monte-Carlo simulation.

Posted Content
TL;DR: In this paper, the authors introduce a general approach to characterize composite fading models based on inverse gamma shadowing and prove that the probability density function and cumulative distribution function of any IG-based composite fading model are directly expressed in terms of a Laplace-domain statistic of the underlying fast fading model and, in some relevant cases, as a mixture of wellknown state-of-the-art distributions.
Abstract: We introduce a general approach to characterize composite fading models based on inverse gamma (IG) shadowing. We first determine to what extent the IG distribution is an adequate choice for modeling shadow fading, by means of a comprehensive test with field measurements and other distributions conventionally used for this purpose. Then, we prove that the probability density function and cumulative distribution function of any IG-based composite fading model are directly expressed in terms of a Laplace-domain statistic of the underlying fast fading model and, in some relevant cases, as a mixture of wellknown state-of-the-art distributions. Also, exact and asymptotic expressions for the outage probability are provided, which are valid for any choice of baseline fading distribution. Finally, we exemplify our approach by presenting several application examples for IG-based composite fading models, for which their statistical characterization is directly obtained in a simple form.

Journal ArticleDOI
01 Feb 2019-Optik
TL;DR: In this article, the performance of cellular and D2D communication underlaid cellular networks has been analyzed using a shared and dedicated resource allocation scheme, and the expressions for cellular success probabilities have been derived and analyzed using stochastic geometry.

Journal ArticleDOI
TL;DR: Non-central limit theorem (NCLT) is introduced, which treats the variance of interference plus noise as a changeable-variance random variable influenced by short-term fading, and the closed-form expression of outage probability for DAS is derived.
Abstract: In this paper, downlink outage probability for distributed antenna systems (DAS) in multicell environment is proposed, while based on maximum desired signal criterion, a single selection transmission scheme (SSTS) is proposed. Usually, adopting central limit theorem (CLT) method, the component of interference plus noise is considered as a fixed-variance Gaussian random variable in most papers. However, the aforementioned method does not reflect the effect of short-term fading on interference and its usage is in the constraints of restrictive conditions. To relax the constraints, non-central limit theorem (NCLT) is introduced, which treats the variance of interference plus noise as a changeable-variance random variable influenced by short-term fading. It is assumed that channels are independent identical Rayleigh fading with propagation path-loss, and the closed-form expression of outage probability for DAS is derived. Finally, simulation results demonstrate the validity of theoretical analysis.