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Hamed S. Al-Raweshidy

Bio: Hamed S. Al-Raweshidy is an academic researcher from Brunel University London. The author has contributed to research in topics: Routing protocol & Network packet. The author has an hindex of 25, co-authored 358 publications receiving 3251 citations. Previous affiliations of Hamed S. Al-Raweshidy include University of Kent & Universities UK.


Papers
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Book
01 Mar 2002
TL;DR: In this paper, the authors present a comparison between Coax and Fiber-Optic Remote Antenna Feeding Links (ROF) for remote antenna feeding and evaluate their performance.
Abstract: Basic Microwave Properties of Optical Links - Insertion Loss and Noise Figure Concepts. A Brief Summary. Direct-Modulated Optical Links. Optical Links of External Intensity Modulation. Heterodyning Microwave/Millimeter Wave Optical Links. Low Cost Optical Fiber Links for Remote Antenna Feeding - Introduction. Requirements for Remote Antenna Feeding Links. Comparison Between Coax and Fiber-Optic Remote Antenna Feeding Links. Laser and Photodiode Nonlinearities and Their Influence on Link Performance. Laser Diode Noise and Its Influence on Link Performance. Low Cost Fiber-Optic Links. Fiber and Multicarrier Effects. Linearization of Fiber-Optic Links. Low Cost Laser Diode Driver and Photoreceiver Design for Fiber-Optic Remote Antenna Feeding Links. Extended Low Cost Fiber-Optic Link Concepts and Applications. Sub-Carrier Optical Fiber Transmission Systems: Fiber-Optic Transmission of Microwave Signals - Fiber-Optic Transmission of Microwave 64-QAM Signals. 256-QAM Sub-Carrier Transmission Using Coding. Laser Nonlinearity Compensation for SCM Applications. Radio Over Fiber Systems for Mobile Applications - Introduction. Coverage Problems. Competing Solutions. Advantages of Radio Over Fiber. Current Technologies. Emerging Technologies. Economic Aspects. Evolution to 3G. Conclusions. Fiber-Optic Radio Networking/Radio Highway Networks/Software Radio NW - Introduction. Various Types of Radio Highway. FDMA. TDMA. CDMA. Chirp Multiple Access (CMA). WCDMA Radio Over Fiber For Mobile Microcellular Communication Networks - WCDMA Computer Simulation Model. Evaluation of the Impact of Spreading Bandwidth. Using The Simulation Approach to Investigate Handover Algorithm performance. The Feasibility of Using Similar Macrodiversity-Combining Technique in the Uplink of ROF Microcellular Systems. Theoretical and Simulation Analysis of Power Control Performance for WCDMA ROF Microcellular Systems. Radio Over Fiber: Current Applications and Future Potential Advantages and Challenges for a Powerful Technology - ROF in the World. Market Acceptance and Competitive Analysis. Third Generation Technological Challenge. Industrial Possibility for ROF and Wireless Infrastructure Convergence. Commercial Advantages Associated With ROF. ROF Multiple Services Communication Systems - Road-to-Vehicle Communications. Wireless Local Loop Systems. Potential for Future Communication Systems. Conclusion.

440 citations

Journal ArticleDOI
TL;DR: In this article, a reconfigurable wideband and multiband C-slot patch antenna with dual-patch elements is proposed and studied, where two parallel C-Slots on the patch elements are employed to perturb the surface current paths for excitation of the dual-band and wideband modes.
Abstract: A reconfigurable wideband and multiband C-Slot patch antenna with dual-patch elements is proposed and studied. It occupies a compact volume of 50 × 50 × 1.57 (3925 mm3), including the ground plane. The antenna can operate in two dual-band modes and a wideband mode from 5 to 7 GHz. Two parallel C-Slots on the patch elements are employed to perturb the surface current paths for excitation of the dual-band and the wideband modes. Two switches, implemented using PIN diodes, are placed on the connecting lines of a simple feed network to the patch elements. Dual-band modes are achieved by switching “ON” either one of the two patch elements, while the wideband mode with an impedance bandwidth of 33.52% is obtained by switching “ON” both patch elements. The frequencies in the dual-band modes can be independently controlled using positions and dimensions of the C-Slots without affecting the wideband mode. The advantage of the proposed antenna is that two dual-band operations and one wideband operation can be achieved using the same dimensions. This overcomes the need for increasing the surface area normally incurred when designing wideband patch antennas. Simulation results are validated experimentally through prototypes. The measured radiation patterns and peak gains show stable responses and are in good agreements. Coupling between the two patch elements plays a major role for achieving the wide bandwidth and the effects of mutual coupling between the patch elements are also studied.

172 citations

Journal ArticleDOI
TL;DR: A novel MPPT technique based on FL control and P&O algorithm is presented and demonstrates that the proposed technique accurately tracks the maximum power point and avoids the drift problem, whilst achieving efficiencies of greater than 99.6%.

122 citations

Journal ArticleDOI
TL;DR: This paper presents a traffic-aware position-based routing protocol for vehicular ad hoc networks (VANETs) suitable for city environments that uses an ant-based algorithm to find a route that has optimum network connectivity.
Abstract: This paper presents a traffic-aware position-based routing protocol for vehicular ad hoc networks (VANETs) suitable for city environments. The protocol is an enhanced version of the geographical source routing (GSR) protocol. The proposed protocol, named efficient GSR, uses an ant-based algorithm to find a route that has optimum network connectivity. It is assumed that every vehicle has a digital map of the streets comprised of junctions and street segments. Using information included in small control packets called ants, the vehicles calculate a weight for every street segment proportional to the network connectivity of that segment. Ant packets are launched by the vehicles in junction areas. In order to find the optimal route between a source and a destination, the source vehicle determines the path on a street map with the minimum total weight for the complete route. The correct functionality of the proposed protocol has been verified, and its performance has been evaluated in a simulation environment. The simulation results show that the packet delivery ratio is improved by more than 10% for speeds up to 70 km/h compared with the VANET routing protocol based on ant colony optimization (VACO) that also uses an ant-based algorithm. In addition, the routing control overhead and end-to-end delay are also reduced.

107 citations

Journal ArticleDOI
TL;DR: A new technique for correcting the gain/phase imbalance in LINC transmitters is presented, which employs a feedback signal to generate an error signal, consisting mainly of intermodulation distortion.
Abstract: A new technique for correcting the gain/phase imbalance in LINC transmitters is presented. The technique employs a feedback signal to generate an error signal, consisting mainly of intermodulation distortion. A direct search method is used to optimise the gain/phase imbalance for correction. An out-of-band radiation suppression of 10 dB was achieved using a signal processing workstation simulation package.

76 citations


Cited by
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01 Jan 2016
TL;DR: The table of integrals series and products is universally compatible with any devices to read and is available in the book collection an online access to it is set as public so you can get it instantly.
Abstract: Thank you very much for downloading table of integrals series and products. Maybe you have knowledge that, people have look hundreds times for their chosen books like this table of integrals series and products, but end up in harmful downloads. Rather than reading a good book with a cup of coffee in the afternoon, instead they cope with some harmful virus inside their laptop. table of integrals series and products is available in our book collection an online access to it is set as public so you can get it instantly. Our book servers saves in multiple locations, allowing you to get the most less latency time to download any of our books like this one. Merely said, the table of integrals series and products is universally compatible with any devices to read.

4,085 citations

Journal ArticleDOI
31 Dec 2008
TL;DR: The concept of Cloud Computing is discussed to achieve a complete definition of what a Cloud is, using the main characteristics typically associated with this paradigm in the literature.
Abstract: This paper discusses the concept of Cloud Computing to achieve a complete definition of what a Cloud is, using the main characteristics typically associated with this paradigm in the literature. More than 20 definitions have been studied allowing for the extraction of a consensus definition as well as a minimum definition containing the essential characteristics. This paper pays much attention to the Grid paradigm, as it is often confused with Cloud technologies. We also describe the relationships and distinctions between the Grid and Cloud approaches.

2,518 citations

Proceedings Article
01 Jan 2003

1,212 citations

Book ChapterDOI
27 Jan 2005
TL;DR: This chapter will focus on evaluating the pairwise error probability with and without CSI, and how the results of these evaluations can be used via the transfer bound approach to evaluate average BEP of coded modulation transmitted over the fading channel.
Abstract: In studying the performance of coded communications over memoryless channels (with or without fading), the results are given as upper bounds on the average bit error probability (BEP). In principle, there are three different approaches to arriving at these bounds, all of which employ obtaining the so-called pairwise error probability , or the probability of choosing one symbol sequence over another for a given pair of possible transmitted symbol sequences, followed by a weighted summation over all pairwise events. In this chapter, we will focus on the results obtained from the third approach since these provide the tightest upper bounds on the true performance. The first emphasis will be placed on evaluating the pairwise error probability with and without CSI, following which we shall discuss how the results of these evaluations can be used via the transfer bound approach to evaluate average BEP of coded modulation transmitted over the fading channel.

648 citations