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This paper introduces a framework for cross-layer management of data transmissions in free-space optical (FSO) systems over atmospheric turbulence channels, in which link layer automatic repeat request (ARQ) and physical layer adaptive modulation and coding (AMC) are integrated to improve the system's spectral efficiency. The system performance is analytically studied in terms of average frame-error...
In this paper we introduce a novel localization algorithm based on visible light communications (VLC) and the trilateration technique. The new algorithm can be used for tracking people or machinery in an underground mining environment. The proposed method utilizes the concept of reference points in order to reduce the location estimation error. The proposed algorithm outperforms the LANDMARC (location...
The commercialization of visible light communication (VLC) technologies is facing up some barriers, such as high complexity, poor mobility, heterogeneous integration with TCP/IP networks, multiaccess, big size and etc. We introduce a practical engineering VLC system, which can solve some of the problems. Utilizing commercial-off-the-shelf technologies, the complexity and size are reduced. A kind of...
This paper presents a framework, called LPV (Linear Parameter Varying) framework, that allows to tackle chaos synchronization issues. Following a tutorial-like form, it is explained how a chaotic map involving polynomial nonlinearities or a piecewise linear map can be rewritten as a polytopic Linear Parameter Varying system. Next, a unified approach to achieve synchronization in the context of secure...
In this paper, a parameter extraction technique of a single- and a two-diode photovoltaic (PV) solar cell models using MATLAB/Simulink are presented. To reduce the computational time, the proposed method uses an accurate iterational technique and limits the inputs to four parameters, which are normally provided by the manufacturers' datasheets. Derived models are validated by plotting their I-V characteristics...
In this paper we propose an optimal resource management scheme for device-to-device (D2D) communications utilising uplink resources in a Single Carrier Frequency Division Multiple Access (SC-FDMA) system, which is the uplink access scheme in the 3GPP-Long Term Evolution (LTE) standard. We consider an arbitrary number of conventional cellular (CC) User Equipments (UEs) and D2D UEs, both utilising the...
This paper proposes an optimization approach for representing instantaneous magnitudes and frequencies of signals. Signals are represented as the products of their magnitudes and the cosines of their phases. Also, both their instantaneous magnitudes and frequencies are positive. These two conditions are posed as linear functional inequality constraints. To have smooth signals, the sum of the total...
The paper proposes an efficient method for solving a one norm equality constrained optimization problem. In fact, this kind of optimization problems is nonconvex. First, the problem is formulated as the least absolute shrinkage and selection operator (LASSO) optimization problem. Then, it is solved by iterative shrinkage algorithms such as the fast iterative shrinkage thresholding algorithm (FISTA)...
Wireless body area networks (WBANs) is an emerging technology which consists of a network composed by miniaturized and intelligent sensor nodes in order to monitor a variety of applications. Due to the lack of overall, wireless technology, the special challenges of WBANs, the IEEE 802.15.6 was proposed to solve these issues in this emerging area and to satisfy the requirements for a monitoring system...
This paper addresses the camera identification based on very low bit rate videos with time varying overall noise pattern statistics. First, the overall noise pattern of each frame of the videos is resized to a column vector. It is found that the elements of the resized vectors approximately follow the Laplace distribution. Hence, the second, the fourth and the sixth order statistic moments of each...
We consider a multirate loss model of a link that accommodates Poisson calls. Calls compete for the available link bandwidth under the combination of the Threshold (TH) and the Bandwidth Reservation (BR) policies. The TH policy limits calls of each service-class up to a threshold, which can be different for each service-class. The BR policy reserves part of the available link bandwidth to benefit...
Multihop free space optical (FSO) system using optical amplify-and-forward (OAF) relaying technique combined with wavelength division multiplexing (WDM) is proposed for all-optical access networks. The proposed system can provide a low cost, flexible, and high-bandwidth access network for multiple users. To investigate the system performance, we consider a special case of dual-hop WDM-FSO system taking...
Spectrally Efficient Frequency Division Multiplexing (SEFDM) is a non-orthogonal multicarrier communication technique that can pack more sub-carriers than Orthogonal Frequency Division Multiplexing (OFDM) in a given bandwidth. In this work, we propose a multi-band architecture named Block-Spectrally Efficient Frequency Division Multiplexing (B-SEFDM) for a large non-orthogonal system. Furthermore,...
Several technologies have been added to wireless communication systems that increase reliability of these systems and afford them higher data rates. These new technologies when combined with the multiple layers of a communications network make the analysis of these systems increasingly complex. The work here analyzes the impact of placing a modulated interfering transmission in the guard band of a...
This work is concerned with the design of a chaotic communication system based on a modified inclusion method. For this, we propose a bidirectional transmitter-receiver communication scheme whereby the transmitter is a Rossler oscillator and the receiver is a corresponding nonlinear high gain observer. The main motivation to employ a bidirectional communication scheme is exclusively to eliminate the...
The use of Extensible Markup Language (XML) for data interchange became standard in most computer systems. The benefits of XML documents are their easy handling, dynamic adjustment to nearly all needs, availability of parsers for any programming language, and the human readability. Despite many advantages of XML, it is still primarily applied in software-based systems. The serious drawback of XML...
In this paper, we address the problem of Vertical Handover (VHO) connection failure which occurs when a handover is initiated but a target network does not have sufficient resources to complete it. Thus it is important to identify Radio Access Technologies (RATs) list of priority for this purpose. We propose a new algorithm using fuzzy logic called Imperative Alternative Media Independent Handover...
Today, the mobile HD-VoIP (High Definition Voice over IP) transmission represents one of the most appropriate communication techniques for the environmental wiretap applications. The perceived speech quality, which is the crucial aspect of a forensic scenario, depends on the QoS guaranteed by the wireless data service of a specific telephone operator and it is mainly due to the radio link quality,...
We propose a robust adaptive time synchronization and frequency offset estimation method for coherent optical orthogonal frequency division multiplexing (CO-OFDM) systems by applying electrical dispersion pre-compensation (pre-EDC) to the pilot symbol. This technique effectively eliminates the timing error due to the fiber chromatic dispersion, thus increasing significantly the accuracy of the frequency...
Spectrum models play a key role in the research of Dynamic Spectrum Access/Cognitive Radio (DSA/CR) systems. Models existing to date are able to characterise the statistical properties of spectrum occupancy in only one of its dimensions (time, frequency or space). However, to the best of the authors' knowledge, there is no model capable to account for the properties of spectrum occupancy in all its...
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