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Recent Submissions

  • Identifying structured light modes in a desert environment using machine learning algorithms

    Ragheb, Amr; Saif, Waddah; Trichili, Abderrahmen; Ashry, Islam; Esmail, Maged Abdullah; Altamimi, Majid; Almaiman, Ahmed; Altubaishi, Essam; Ooi, Boon S.; Alouini, Mohamed-Slim; Alshebeili, Saleh (Optics Express, The Optical Society, 2020-03-12) [Article]
    The unique orthogonal shapes of structured light beams have attracted researchers to use as information carriers. Structured light-based free space optical communication is subject to atmospheric propagation effects such as rain, fog, and rain, which complicate the mode demultiplexing process using conventional technology. In this context, we experimentally investigate the detection of Laguerre Gaussian and Hermite Gaussian beams under dust storm conditions using machine learning algorithms. Different algorithms are employed to detect various structured light encoding schemes including the use of a convolutional neural network (CNN), support vector machine, and k-nearest neighbor. We report an identification accuracy of 99% under a visibility level of 9 m. The CNN approach is further used to estimate the visibility range of a dusty communication channel.
  • Ultra-Reliable Low-Latency Transmission of Small Data over Fading Channels: A Data-Oriented Analysis

    Yang, Hong-Chuan; Choi, Seyeong; Alouini, Mohamed-Slim (IEEE Communications Letters, IEEE, 2019-12-13) [Article]
    A data-oriented approach has been recently proposed that simultaneously supports ultra-high reliability and low latency in wireless transmission systems. In this letter, we analyze the performance of small data transmissions over fading channels in terms of a data-oriented performance metric. Through analytical results and associated numerical examples, we demonstrate the effectiveness of rate/power adaptive transmission and diversity combining in achieving ultra-reliable low-latency transmissions.
  • Performance Analysis of Multiuser FSO/RF Network Under Non-Equal Priority with P-Persistence Protocol

    Rakia, Tamer; Gebali, Fayez; Yang, Hong-Chuan; Alouini, Mohamed-Slim (IEEE Transactions on Wireless Communications, IEEE, 2019-12-12) [Article]
    This paper presents and analyzes a novel multiuser network based on hybrid free-space optical (FSO)/radiofrequency (RF) transmission system, where every user is serviced by a primary FSO link. When more than one FSO link fail, the central node services these corresponding users of non-equal priority by using a common backup RF link according to a p persistence servicing protocol. A novel discrete-time Markov chain model is developed for the proposed network, where different transmission rates over RF and FSO links are assumed. We investigate the throughput from central node to the user, the average size of the transmit buffer allocated for every user, the frame queuing delay in the transmit buffer, the efficiency of the queuing system, the frame loss probability, and the RF link utilization. Numerical examples show that transmitting a data frame with probability p when using the common backup RF link achieves considerable network performance improvement while ensuring high-priority users enjoy better performance. Meanwhile, the performance of low-priority users approaches the performance when using equal priority protocol to serve all the remote users.
  • Ultraviolet-to-blue color-converting scintillating-fibers photoreceiver for 375-nm laser-based underwater wireless optical communication

    Kang, Chun Hong; Trichili, Abderrahmen; Alkhazragi, Omar; Zhang, Huafan; Subedi, Ram Chandra; Guo, Yujian; Mitra, Somak; Shen, Chao; Roqan, Iman S.; Ng, Tien Khee; Alouini, Mohamed-Slim; Ooi, Boon S. (Optics Express, The Optical Society, 2019-10-08) [Article]
    Underwater wireless optical communication (UWOC) can offer reliable and secure connectivity for enabling future internet-of-underwater-things (IoUT), owing to its unlicensed spectrum and high transmission speed. However, a critical bottleneck lies in the strict requirement of pointing, acquisition, and tracking (PAT), for effective recovery of modulated optical signals at the receiver end. A large-area, high bandwidth, and wide-angle-of-view photoreceiver is therefore crucial for establishing a high-speed yet reliable communication link under non-directional pointing in a turbulent underwater environment. In this work, we demonstrated a large-area, of up to a few tens of cm2, photoreceiver design based on ultraviolet(UV)-to-blue color-converting plastic scintillating fibers, and yet offering high 3-dB bandwidth of up to 86.13 MHz. Tapping on the large modulation bandwidth, we demonstrated a high data rate of 250 Mbps at bit-error ratio (BER) of 2.2 × 10−3 using non-return-to-zero on-off keying (NRZ-OOK) pseudorandom binary sequence (PRBS) 210-1 data stream, a 375-nm laser-based communication link over the 1.15-m water channel. This proof-of-concept demonstration opens the pathway for revolutionizing the photodetection scheme in UWOC, and for non-line-of-sight (NLOS) free-space optical communication.
  • Secure mmWave Communications in Cognitive Radio Networks

    Zhao, Hui; Zhang, Jiayi; Yang, Liang; pan, Gaofeng; Alouini, Mohamed-Slim (IEEE Wireless Communications Letters, Institute of Electrical and Electronics Engineers (IEEE), 2019-08-22) [Article]
    In this letter, the secrecy performance in cognitive radio networks (CRNs) over fluctuating two-ray (FTR) channels, which is used to model the milimeter wave channel, is investigated in terms of the secrecy outage probability (SOP). Specifically, we consider the case where a source (S) transmits confidential messages to a destination (D), and an eavesdropper wants to wiretap the information from S to D. In a CRN framework, we assume that the primary user shares its spectrum with S, where S adopts the underlay strategy to control its transmit power without impairing the quality of service of the primary user. After some mathematical manipulations, an exact analytical expression for the SOP is derived. In order to get physical and technical insights into the effect of the channel parameters on the SOP, we derive an asymptotic formula for the SOP in the high signal-to-noise ratio region of the S-D link. We finally show some selected Monte-Carlo simulation results to validate the correctness of our derived analytical expressions.
  • Generalized Beamspace Modulation using Multiplexing for mmWave MIMO

    Guo, Shuaishuai; Zhang, Haixia; Zhang, Peng; Zhao, Pengjie; Wang, Leiyu; Alouini, Mohamed-Slim (2019 IEEE International Conference on Communications, ICC 2019, IEEE, 2019-07-16) [Conference Paper]
    Spatial multiplexing (SMX) multiple-input multiple-output (MIMO) over the best beamspace was considered as the best solution for millimeter wave (mm ave) communications regarding spectral efficiency (SE), referred as the best beamspace selection (BBS) solution. The equivalent MIMO water-filling (F-MIMO) channel capacity was treated as an unsurpassed SE upper bound. Recently, researchers have proposed various schemes trying to approach the benchmark and the performance bound. In this paper, we challenge the benchmark and the corresponding bound by proposing a better transmission scheme that achieves higher SE, namely the Generalized Beamspace Modulation using Multiplexing (GBMM). Inspired by the concept of spatial modulation, we not only use the selected beamspace to transmit information but also use the selection operation to carry information. e prove that GBMM is superior to BBS in terms of SE and can break through the well known upper bound. That is, GBMM renews the upper bound of the system SE. e investigate SE-oriented precoder activation probability optimization, fully-digital precoder design and hybrid precoder design for GBMM. Comparisons with the benchmark (i.e., F-MIMO channel capacity) are made under different system configurations to show the superiority of GBMM.
  • On the Performance of Quantum Key Distribution FSO Systems Under a Generalized Pointing Error Model

    Zhao, Hui; Alouini, Mohamed-Slim (IEEE Communications Letters, Institute of Electrical and Electronics Engineers (IEEE), 2019-07-15) [Article]
    In this letter, the performance of a quantum key distribution (QKD) free-space optical (FSO) system is analyzed while taking a generalized pointing error model into account. More specifically, closed-form expressions for the average received powers at both the legitimate receiver and eavesdropper are derived. In addition, their corresponding asymptotic results valid in the high telescope gain regime are also presented. To capture the secure performance, we also investigate the ratio of received powers at the eavesdropper and at the legitimate receiver. Further, in some special cases, we find the optimal telescope gains for the received powers at both the legitimate receiver and eavesdropper, as well as the power ratio, which is important and useful for a secure QKD FSO system design. Finally, some selected numerical results are presented to illustrate the mathematical formalism and validate the accuracy of the derived analytical expressions.
  • Producing OAM Information Carriers using Micro-structured Spiral Phase Plates

    Stegenburgs, Edgars; Bertoncini, Andrea; Trichili, Abderrahmen; Alias, Mohd Sharizal; Ng, Tien Khee; Alouini, Mohamed-Slim; Liberale, Carlo; Ooi, Boon S. (Institute of Electrical and Electronics Engineers (IEEE), 2019-07-01) [Conference Paper]
    We report on small foot-print spiral phase plates for orbital angular momentum (OAM) light beam generation used in free space communication. A modal decomposition process confirms high purity of the generated beams at 980-nm wavelength. © 2019 The Author(s)
  • Visible diode lasers for high bitrate underwater wireless optical communications

    Ooi, Boon S.; Sun, Xiaobin; Alkhazragi, Omar; Guo, Yujian; Ng, Tien Khee; Alouini, Mohamed-Slim (Optical Fiber Communication Conference (OFC) 2019, The Optical Society, 2019-02-25) [Conference Paper]
    This talk provides an overview of the latest underwater wireless optical communication (UWOC) research from the system to the device level. Besides, studies investigating underwater channel characterization are also described.
  • Accurate Outage Probability Evaluation of Equal Gain Combining Receivers

    Rached, Nadhir B.; Kammoun, Abla; Alouini, Mohamed-Slim; Tempone, Raul (2018 IEEE Global Communications Conference (GLOBECOM), Institute of Electrical and Electronics Engineers (IEEE), 2019-02-21) [Conference Paper]
    We consider the evaluation of the outage probability (OP) for L -branch equal gain combining diversity receivers operating over fading channels, i.e. equivalently the cumulative distribution function (CDF) of the sum of the L channel envelopes. Generally, closed-form expressions of the OP values are out of reach. Moreover, the use of naive Monte Carlo (MC) simulations is not a good alternative since it is expensive in terms of number of samples when small values of OP are considered. In this paper, we use the concept of importance sampling (IS), being known to yield accurate estimates using few number of simulations runs. The proposed IS scheme is essentially based on sample rejection where the IS probability density function (PDF) is the truncation of the underlying PDF over the L dimensional sphere. It assumes the knowledge of the CDF of the sum of the L channel gains in a closed-form expression. Such an assumption is not restrictive since it holds for various challenging fading models. As an illustration, we apply the proposed estimator to the cases of independent Rayleigh, correlated Rayleigh, and independent and identically distributed Rice fading channels and prove that it achieves the well-desired bounded relative error property. Finally, we validate these theoretical results through some selected experiments.
  • Extended Delivery Time Analysis of Cognitive Data Transmission Over Multiple Primary Channels

    Khalid, Muhammad N.; Usman, Muneer; Yang, Hong-Chuan; Alouini, Mohamed-Slim (2018 IEEE Global Communications Conference (GLOBECOM), Institute of Electrical and Electronics Engineers (IEEE), 2019-02-21) [Conference Paper]
    Cognitive radio (CR) systems can improve radio spectrum utilization by allowing secondary access of underutilized spectrum resources. With interweave cognitive implementation, secondary users have to wait for spectrum opportunities before their transmission. Therefore, the total delivery time of secondary transmission consists of both waiting slots and transmission slots. In this work, we study the resulting extended delivery time (EDT) of secondary transmission for a fixed amount of data over multiple primary channels. In particular, a birth-death process is introduced to model the number of available primary channels, based on which, we derive the distribution function of the EDT for both continuous and periodic sensing cases. We also present selected numerical results to illustrate the mathematical formulation.
  • Joint Scheduling and Power Adaptation in NOMA-Based Fog-Radio Access Networks

    Randrianantenaina, Itsikiantsoa; Kaneko, Megumi; Dahrouj, Hayssam; ElSawy, Hesham; Alouini, Mohamed-Slim (2018 IEEE Global Communications Conference (GLOBECOM), Institute of Electrical and Electronics Engineers (IEEE), 2019-02-21) [Conference Paper]
    Non-Orthogonal Multiple Access (NOMA) is a promising technology for 5G that enables each resource unit to simultaneously serve multiple users. This work evaluates the potential benefit of joint scheduling and power adaptation in NOMA- based downlink in Fog-Radio Access Networks (FRAN). We consider the downlink of a FRAN, where the Fog Access Points (FAPs) are connected to central cloud baseband units (BBUs) through capacity-constrained fronthaul links. The FAPs adopt a two-user NOMA scheme, within each resource block (RB), to serve a common set of users. The paper formulates an optimization problem which maximizes a network-wide {rate-based utility} function subject to fronthaul- capacity constraints, so as to determine both the user- to-FAP assignment and the power levels of the users served by each FAP. The main contribution of the paper is solving this mixed-integer non-convex optimization problem using a two- step centralized-distributed approach, which is aligned with FRAN operation that {aims to} %relies on partially shifting the network control to the FAPs so as to overcome delays due to fronthaul rate constraints. The assignment step is first solved at the centralized BBU pool by reformulating the problem such that the Hungarian algorithm is applicable. The power {adaptation} is then solved at every FAP using a barrier method. Simulation results show that the proposed NOMA-based algorithm outperforms conventional Orthogonal Multiple Access (OMA) algorithms, even with stringent fronthaul limitations. The proposed algorithm further shows an appreciable {performance trade-off} between the rate and fairness metrics.
  • On the Reciprocity of Underwater Turbulent Channels

    Guo, Yujian; Trichili, Abderrahmen; Alkhazragi, Omar; Ashry, Islam; Ng, Tien Khee; Alouini, Mohamed-Slim; Ooi, Boon S. (IEEE Photonics Journal, Institute of Electrical and Electronics Engineers (IEEE), 2019-02-12) [Article]
    Through a series of experiments incorporating two counter-propagating communication channels, we investigate the reciprocity nature of underwater turbulence. Bit error rate measurement and statistical data analysis reveal a high reciprocal nature of turbulence induced by the presence of bubbles, temperature, and salinity. We further demonstrate the effect of distortions at the beam level that could potentially be used for underwater communication system design considerations.
  • Precise Performance Analysis of Dual-Hop Mixed RF/Unified-FSO DF Relaying With Heterodyne Detection and Two IM-DD Channel Models

    Al-Ebraheemy, Omer Mahmoud Salih; Salhab, Anas M.; Chaaban, Anas; Zummo, Salam A.; Alouini, Mohamed-Slim (IEEE Photonics Journal, Institute of Electrical and Electronics Engineers (IEEE), 2019-01-08) [Article]
    This paper provides precise performance analysis of the dual-hop mixed radio frequency (RF)/unified free space optical (FSO) decode-and-forward (DF) relaying system, in which the heterodyne detection and the intensity modulation-direct detection (IM-DD) are taken into account for FSO detection. To this end, we derive closed-form expressions for the outage probability, average bit error rate (BER), and the ergodic channel capacity of this system. In this analysis, we utilize, for the first time as per our knowledge, a precise channel capacity result for the IM-DD channel. Moreover, this is the first time that not only the (IM-DD input-independent) but also the (IM-DD cost-dependent) additive white Gaussian noise (AWGN) channel is considered in such system analyses. Additionally in this study, we assume that the first hop (RF link) follows Nakagami-m fading, and the second hop (FSO link) follows Málaga (M) turbulence with pointing errors. These fading and turbulence models contain other models (such as Rayleigh and Gamma-Gamma) as special cases, thus, our analyses can be seen as a generalized one from the RF and FSO fading models point of view. Also, in BER derivation, we assume that the modulation schemes in the two hops can be different, since not all modulation schemes are suitable for IM-DD FSO links. In addition, the system performance is investigated asymptotically at high signal to noise ratios. This investigation leads to new nonreported coding gain and diversity order analyses of such system. Interestingly, we find that in the FSO hop, at high transmitted powers, all the considered FSO detectors result in the same diversity order. Furthermore, we provide simulation results that verify the accuracy of the obtained analytical and asymptotic expressions.
  • Artificial Noise Based Beamforming for the MISO VLC Wiretap Channel

    Arfaoui, Mohamed Amine; Zaid, Hajar; Rezki, Zouheir; Ghrayeb, Ali; Chaaban, Anas; Alouini, Mohamed-Slim (IEEE Transactions on Communications, Institute of Electrical and Electronics Engineers (IEEE), 2018-12-25) [Article]
    This paper investigates the secrecy performance of the multiple-input single-output (MISO) visible light communication (VLC) wiretap channel. The considered system model comprises three nodes: a transmitter (Alice) equipped with multiple fixtures of LEDs, a legitimate receiver (Bob) and an eavesdropper (Eve), each equipped with one photo-diode (PD). The VLC channel is modeled as a real-valued amplitude-constrained Gaussian channel. Eve is assumed to be randomly located in the same area as Bob. Due to this, artificial noise (AN)-based beamforming is adopted as a transmission strategy in order to degrade Eve’s signal-to-noise ratio (SNR). Assuming discrete input signaling, we derive an achievable secrecy rate in a closed-form expression as a function of the beamforming vectors and the input distribution. We investigate the average secrecy performance of the system using stochastic geometry to account for the location randomness of Eve. We also adopt the truncated discrete generalized normal (TDGN) as a discrete input distribution. We present several examples through which we confirm the accuracy of the analytical results via Monte Carlo simulations. The results also demonstrate that the TDGN distribution, albeit being not optimal, yields performance close to the secrecy capacity.
  • Physical Layer Security For Dual-Hop VLC/RF Communication Systems

    Liao, Zhaohui; Yang, Liang; Chen, Jianchao; Yang, Hong-Chuan; Alouini, Mohamed-Slim (IEEE Communications Letters, Institute of Electrical and Electronics Engineers (IEEE), 2018-10-04) [Article]
    In this letter, we investigate the physical layer security of a mixed visible light communication (VLC)/radio-frequency (RF) system. More specifically, the relay can extract the direct current component and collect energy from the optical signal in the VLC link and then use this collected energy to retransmit data though the RF link. With this setup, the exact performance expressions for secure outage probability and average secrecy capacity are derived in closed form. We also provide asymptotic results to investigate the effect of different system parameters on the system performance. Finally, we present numerical results to illustrate our analytical result.
  • Full-Duplex Energy-Harvesting Enabled Relay Networks in Generalized Fading Channels

    Rabie, Khaled; Adebisi, Bamidele; Nauryzbayev, Galymzhan; Badarneh, Osamah S.; Li, Xingwang; Alouini, Mohamed-Slim (IEEE Wireless Communications Letters, Institute of Electrical and Electronics Engineers (IEEE), 2018-10-01) [Article]
    This paper analyzes the performance of a full-duplex decode-and-forward relaying network over the generalized κ-μ fading channel. The relay is energy-constrained and relies entirely on harvesting the power signal transmitted by the source based on the time-switching relaying protocol. A unified analytical expression for the ergodic outage probability is derived for the system under consideration. This is then used to derive closed-form analytical expressions for three special cases of the κ-μ fading model, namely, Rice, Nakagami-m and Rayleigh. Monte Carlo simulations are provided throughout to validate our analysis.
  • System Modeling of Virus Transmission and Detection in Molecular Communication Channels

    Khalid, Maryam; Amin, Osama; Ahmed, Sajid; Alouini, Mohamed-Slim (2018 IEEE International Conference on Communications (ICC), Institute of Electrical and Electronics Engineers (IEEE), 2018-08-20) [Conference Paper]
    Aerosol Transmission is one of the major spread mechanism for diseases and is responsible for transmission of virus over long distances. The advancement in nanotechnology has resulted in sensors and systems that allow us to deal with nanosized biological entities such as virus and bacteria. In this work, the idea of viewing virus transmission through aerosols and their transport as a molecular communication problem is introduced. In such problems one has little or no control over transmission, however, a robust receiver can be designed using nano-biosensors for information extraction. Thus, the objective of this work is to treat viral aerosol spread as a blind communication problem and present a mathematical model for it. Specifically, we study the virus transmission from an engineering perspective and derive an end-to-end mathematical model for virus transmission in the atmosphere. The receiver architecture composed of air sampler and Silicon Nanowire field effect transistor is also discussed. Furthermore, a detection problem is formulated and simulation results are reported that justify the feasibility of such setups in bio-monitoring applications.
  • On the Uplink of Large-Scale MIMO Systems with Correlated Ricean Fading Channels

    Boukhedimi, Ikram; Kammoun, Abla; Alouini, Mohamed-Slim (2018 IEEE International Conference on Communications (ICC), Institute of Electrical and Electronics Engineers (IEEE), 2018-08-20) [Conference Paper]
    In this work, we focus on the uplink (UL) of a single-cell large-scale multi-user MIMO system where K mono-antenna users communicate with a BS equipped with N antennas. This latter estimates the Ricean correlated channels based on training symbols and uses maximum-ratio- combining or linear-minimum-mean-square-error receivers for signal processing. Assuming a fixed number of users with an asymptotic antenna regime, we derive closed-form approximations of the achievable UL rates as a function of the system's parameters, the Ricean factors and the training sequence's length. Accordingly, these expressions are instructive in how the aforementioned parameters impact the performances. Plus, a different processing approach using only the statistics of the channels is investigated and found to be a judicious choice when the Ricean factor is high enough. Although our analytical results are based on a large antenna-limit, we show by simulations that they provide very accurate approximations even for finite system dimensions.
  • Generalized Cooperative Spectrum Sharing Scheme for Internet of Things Systems

    Hagag, Adham; Amin, Osama; Cao, Lei; Viswanathan, Ramanarayanan; Alouini, Mohamed-Slim (2018 IEEE International Conference on Communications (ICC), Institute of Electrical and Electronics Engineers (IEEE), 2018-08-20) [Conference Paper]
    A generalized cooperative spectrum sharing (GCSS) scheme for machine-to-machine (M2M) communications is pro- posed in internet-of-things (IoT) systems. The proposed scheme makes use of the existence of massive connected machines to overcome the challenges of spectrum scarcity while avoiding interference and meeting the green requirements of IoT systems. The cooperative proposed scheme extends the coverage of M2M wireless network as well as increasing the throughput while reducing the energy consumption of the connected low power devices. The performance of the GCSS scheme is evaluated analytically by the outage performance by deriving the outage probability. Furthermore, a numerical simulations are presented to support the theoretical findings.

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