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IEEE Conference on Wireless Communications and Networking

作者： Muhammad Talha Malik Md. Jahangir Hossain Mohamed-Slim Alouini School of Engineering The University of British Columbia Kelowna BC Canada Computer Electrical and Mathematical Science and Engineering (CEMSE) Division King Abdullah University of Science & Technology (KAUST) Makkah Saudia Arabia

Experimental measurements have shown that the noise in many communication channels is non-Gaussian. Bit interleaved coded modulation (BICM) is very popular for spectrally efficient transmission. Recent results have shown that the performance of BICM using convolutional codes in non-fading channels can be significantly improved if the coded bits are not interleaved at all. This particular BICM design is called BICM trivial (BICM-T). In this paper, we analyze the performance of a generalized BICM-T design for communication over Gaussian mixture noise (GMN) channels. The results disclose that for an optimal bit error rate (BER) performance, the use of an interleaver in BICM for GMN channels depends upon the strength of the impulsive noise components in the Gaussian mixture. The results presented for 16-QAM show that the BICM-T can result in gains up to 1.5 dB for a target BER of 10 -6 if the impulsive noise in the Gaussian mixture is below a certain threshold level. The simulation results verify the tightness of developed union bound (UB) on BER performance.

关键词： Noise Bit error rate Receivers Decoding Noise measurement Constellation diagram

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BICM-Based Cooperative Communication Systems with Relay Selection: Constellation and Multiplexer Design

BICM-Based Cooperative Communication Systems with Relay Sele...

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IEEE Conference on Vehicular technology (VTC)

We propose a new bit-interleaved coded modulation (BICM)-based cooperative communication system where different BICM modules can be optimized jointly considering the average signal to noise ratios of the direct and the two-hop Rayleigh fading channels. As such, the full benefit of BICM can be exploited in the context of cooperative communication. Our design considers cooperative communication systems with so called max-min relay selection scheme that has no loss in performance in terms of diversity-multiplexing trade off in orthogonal cooperation. The presented numerical results for rate 1/2 convolutional code with 8-ary pulse amplitude modulation equivalently 64-ary quadrature amplitude modulation show that the proposed design can offer gains up to 1.4 dB over the traditional BICM design for a target bit error rate of 10 -6 . Moreover the results show that the amount of gain depends on the relays' positions and increases with the number of relays available for selection.

关键词： Relays Bit error rate Cooperative communication Multiplexing Signal to noise ratio Optimization Modulation

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On the low SNR capacity of MIMO fading channels with imperfect channel state information

On the low SNR capacity of MIMO fading channels with imperfe...

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International Symposium on Modeling and Optimization in Mobile, Ad Hoc, and Wireless Networks (WiOpt)

作者： Fatma Benkhelifa Abdoulaye Tall Zouheir Rezki Mohamed-Slim Alouini Computer Electrical and Mathematical Science and Engineering (CEMSE) Division King Abdullah University of Science and Technology (KAUST) Thuwal Makkah Province Saudi Arabia Orange Labs France

ISBN: (纸本)9781479953059

The capacity of Multiple Input Multiple Output (MIMO) Rayleigh fading channels with full knowledge of channel state information (CSI) at both the transmitter and the receiver (CSI-TR) has been shown recently to scale at low Signal-to-Noise Ratio (SNR) essentially as SNR log(1=SNR), independently of the number of transmit and receive antennas. In this paper, we investigate the ergodic capacity of MIMO Rayleigh fading channel with estimated channel state information at the transmitter (CSI-T) and possibly imperfect channel state information at the receiver (CSI-R). Our framework can be seen as a generalization of previous works as it can capture the perfect CSI-TR as a special case when the estimation error variance goes to zero. In our work, we mainly focus on the low SNR regime and we show that the capacity scales as (1-α) SNR log(1=SNR), where α is the estimation error variance. This characterization shows the loss of performance due to error estimation over the perfect channel state information at both the transmitter and the receiver. As a by-product of our new analysis, we show that our framework can also be extended to characterize the capacity of MIMO Rician fading channels at low SNR with possibly imperfect CSI-T and CSI-R.

关键词： Signal to noise ratio Fading Noise measurement Rician channels

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Mobile Sensor Networks for Leak and Backflow Detection in Water Distribution Systems

Mobile Sensor Networks for Leak and Backflow Detection in Wa...

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IEEE International Conference on Advanced Information Networking and Applications

作者： M. Agumbe Suresh L. Smith A. Rasekh R. Stoleru M. K. Banks B. Shihada Department of Computer Science and Engineering Texas A&M University Department of Civil Engineering Texas A&M University Department of Computer Science King Abdullah University of Science and Technology

ISBN: (纸本)9781479936311

Leak and backflow detection are essential aspects of Water Distribution System (WDS) monitoring. Most existing solutions for leak/backflow detection in WDSs focus on the placement of expensive static sensors located strategically. In contrast to these, we propose a solution whereby mobile sensors (i.e., their movement aided only by the inherent water flow in the system) detect leaks/backflow. Information about the leaks/backflow is collected from the sensors either by physically capturing them, or through wireless communication. Specifically, we propose models to maximize leak/backflow detection given a cost constraint (a limit on the number of sensors). Through extensive simulations, we demonstrate the superior performance of our proposed solution when compared with the state of the art solutions (e.g., algorithms/protocols and analysis).

关键词： Backflow Water WDS

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A discontinuous galerkin time domain-boundary integral method for analyzing transient electromagnetic scattering

A discontinuous galerkin time domain-boundary integral metho...

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Antennas and Propagation Society International Symposium

作者： Ping Li Li Jun Jiang Yifei Shi Hakan Bağcı Dept. of Electrical and Electronic Engineering The University of Hong Kong Hong Kong China Dept. of Computer Electrical King Abdullah University of Science and Technology Thuwal Saudi Arabia

This paper presents an algorithm hybridizing discontinuous Galerkin time domain (DGTD) method and time domain boundary integral (BI) algorithm for 3-D open region electromagnetic scattering analysis. The computational domain of DGTD is rigorously truncated by analytically evaluating the incoming numerical flux from the outside of the truncation boundary through BI method based on the Huygens' principle. The advantages of the proposed method are that it allows the truncation boundary to be conformal to arbitrary (convex/ concave) scattering objects, well-separated scatters can be truncated by their local meshes without losing the physics (such as coupling/multiple scattering) of the problem, thus reducing the total mesh elements. Furthermore, low frequency waves can be efficiently absorbed, and the field outside the truncation domain can be conveniently calculated using the same BI formulation. Numerical examples are benchmarked to demonstrate the accuracy and versatility of the proposed method.

关键词： Bismuth Time-domain analysis Method of moments Electromagnetic scattering Equations Mathematical model

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A FMM-FFT accelerated hybrid volume surface integral equation solver for electromagnetic analysis of re-entry space vehicles

A FMM-FFT accelerated hybrid volume surface integral equatio...

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USNC-URSI Radio science Meeting (Joint with AP-S Symposium)

作者： Abdulkadir C. Yücel Luis J. Gomez Yang Liu Hakan Bağcı Eric Michielssen University of Michigan Ann Arbor MI US Department of Electrical Engineering and Computer Science University of Michigan Ann Arbor MI USA King Abdullah University of Science and Technology Thuwal SA

Summary form only given. Space vehicles that re-enter the atmosphere often experience communication blackout. The blackout occurs when the vehicle becomes engulfed in plasma produced by interactions between the vehicle surface and the atmosphere. The plasma often is concentrated in a relatively thin shell around the vehicle, with higher densities near its nose than rear. A less structured, sometimes turbulent plasma wake often trails the vehicle. The plasma shell severely affects the performance of side-mounted antennas as it alters their characteristics (frequency response, gain patterns, axial ratio, and impedance) away from nominal, free-space values, sometimes entirely shielding the antenna from the outside world. The plasma plume/turbulent wake similarly affect the performance of antennas mounted at the back of the vehicle. The electromagnetic characteristics of the thin plasma shell and plume/turbulent wake heavily depend on the type of re-entry trajectory, the vehicle's speed, angles of attack, and chemical composition, as well as environmental conditions. To analyze the antennas' performance during blackout and to design robust communication antennas, efficient and accurate simulation tools for charactering the antennas' performance along the trajectory are called for.

关键词： Antennas Plasmas Surface impedance Space vehicles Computational modeling

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Transmit power optimization for green multihop relaying over Nakagami-m fading channels

Transmit power optimization for green multihop relaying over...

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International Conference on Communications and Networking, ComNet

作者： Itsikiantsoa Randrianantenaina Mustapha Benjillali Mohamed-Slim Alouini Computer Electrical and Mathematical Science and Engineering (CEMSE) Division King Abdullah University of Science and Technology (KAUST) Thuwal Saudi Arabia Communication Systems Department INPT Rabat Morocco

In this paper, we investigate the optimal transmit power strategy to maximize the energy efficiency of a multihop relaying network. Considering the communication between a source and a destination through multiple Amplify-and-Forward relays, we first give the expression of the total instantaneous system energy consumption. Then, we define the energy efficiency in our context and obtain its expression in closed-form when the communication is over Nakagami-m fading channels. The analysis yields to the derivation of a global transmit power strategy where each individual node is contributing to the end-to-end overall energy efficiency. Numercial results are presented to illustrate the analysis. Comparison with Monte Carlo simulation results confirms the accuracy of our derivations, and assesses the gains of the proposed power optimization strategy.

关键词： Relays Fading Energy consumption Wireless communication Signal to noise ratio Resource management Green products

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Outage performance analysis of underlay cognitive RF and FSO wireless channels

Outage performance analysis of underlay cognitive RF and FSO...

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International Workshop on Optical Wireless Communications

作者： Imran Shafique Ansari Mohamed M. Abdallah Mohamed-Slim Alouini Khalid A. Qaraqe Computer Electrical and Mathematical Sciences and Engineering (CEMSE) King Abdullah University of Science and Technology (KAUST) Thuwal Makkah Province Kingdom of Saudi Arabia Department of Electrical and Computer Engineering Texas A&M University at Qatar Doha Qatar

In this work, the outage performance analysis of a dual-hop transmission system composed of asymmetric radio frequency (RF) channel cascaded with a free-space optical (FSO) link is presented. For the RF link, an underlay cognitive network is considered where the secondary users share the spectrum with licensed primary users. Indoor femtocells act as a practical example for such networks. More specifically, it is assumed that the RF link applies power control to maintain the interference at the primary network below a predetermined threshold. While the RF channel is modeled by the Rayleigh fading distribution, the FSO link is modeled by a unified Gamma-Gamma turbulence distribution. The FSO link accounts for pointing errors and both types of detection techniques (i.e. heterodyne detection as well as intensity modulation/direct detection (IM/DD)). With this model, a new exact closed-form expression is derived for the outage probability of the end-to-end signal-to-noise ratio of these systems in terms of the Meijer's G function and the Fox's H functions under fixed amplify-and-forward relay scheme. All new analytical results are verified via computer-based Monte-Carlo simulations and are illustrated by some selected numerical results.

关键词： Radio frequency Adaptive optics Signal to noise ratio Relays Wireless communication Interference Optical fiber communication

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Nonlinear effects in optical pumping of a cold and slow atomic beam

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Physical Review A 2015年第4期92卷 043408-043408页

作者： N. Porfido N. N. Bezuglov M. Bruvelis G. Shayeganrad S. Birindelli F. Tantussi I. Guerri M. Viteau A. Fioretti D. Ciampini M. Allegrini D. Comparat E. Arimondo A. Ekers F. Fuso Dipartimento di Fisica Enrico Fermi Università di Pisa 56127 Pisa Italy Faculty of Physics St. Petersburg State University 198904 St. Petersburg Russia Department of Physics University ITMO 197101 St. Petersburg Russia Institute of Atomic Physics and Spectroscopy University of Latvia LV-1586 Riga Latvia Orsay Physics TESCAN Orsay 13710 Fuveau France Istituto Nazionale di Ottica INO-CNR 56124 Pisa Italy Consorzio Nazionale Interuniversitario per le Scienze Fisiche della Materia CNISM Sezione di Pisa 56127 Pisa Italy Laboratoire Aimé Cotton CNRS Université Paris-Sud ENS Cachan 91405 Orsay France Computer Electrical and Mathematical Sciences and Engineering Division King Abdullah University of Science and Technology Thuwal 23955-6900 Kingdom of Saudi Arabia

By photoionizing hyperfine (HF) levels of the Cs state 62P3/2 in a slow and cold atom beam, we find how their population depends on the excitation laser power. The long time (around 180μs) spent by the slow atoms inside the resonant laser beam is large enough to enable exploration of a unique atom-light interaction regime heavily affected by time-dependent optical pumping. We demonstrate that, under such conditions, the onset of nonlinear effects in the population dynamics and optical pumping occurs at excitation laser intensities much smaller than the conventional respective saturation values. The evolution of population within the HF structure is calculated by numerical integration of the multilevel optical Bloch equations. The agreement between numerical results and experiment outcomes is excellent. All main features in the experimental findings are explained by the occurrence of “dark” and “bright” resonances leading to power-dependent branching coefficients.

关键词： Optical pumping

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Indoor localization using unsupervised manifold alignment with geometry perturbation

Indoor localization using unsupervised manifold alignment wi...

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IEEE Conference on Wireless Communications and Networking

作者： Khaqan Majeed Sameh Sorour Tareq Y. Al-Naffouri Shahrokh Valaee Electrical Engineering Department King Fahd University of Petroleum and Minerals (KFUPM) Dhahran Saudi Arabia CEMSE Division King Abdullah University of Science and Technology (KAUST) Thuwal Saudi Arabia Department of Electrical and Computer Engineering University of Toronto Toronto ON Canada

ISBN: (纸本)9781479930845

The main limitation of deploying/updating Received Signal Strength (RSS) based indoor localization is the construction of fingerprinted radio map, which is quite a hectic and time-consuming process especially when the indoor area is enormous and/or dynamic. Different approaches have been undertaken to reduce such deployment/update efforts, but the performance degrades when the fingerprinting load is reduced below a certain level. In this paper, we propose an indoor localization scheme that requires as low as 1% fingerprinting load. This scheme employs unsupervised manifold alignment that takes crowd sourced RSS readings and localization requests as source data set and the environment's plan coordinates as destination data set. The 1% fingerprinting load is only used to perturb the local geometries in the destination data set. Our proposed algorithm was shown to achieve less than 5 m mean localization error with 1% fingerprinting load and a limited number of crowd sourced readings, when other learning based localization schemes pass the 10 m mean error with the same information.

关键词： Geometry Manifolds Vectors Calibration Indoor environments Zirconium Mobile computing

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