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Desmond C. McLernon

Bio: Desmond C. McLernon is an academic researcher from University of Leeds. The author has contributed to research in topics: Communication channel & Cellular network. The author has an hindex of 18, co-authored 134 publications receiving 1050 citations.


Papers
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Proceedings ArticleDOI
27 Jun 2016
TL;DR: It is demonstrated that by intelligently selecting the number of drones and their corresponding altitudes, ground users coverage can be significantly enhanced without incurring significant performance penalty to the mobile users which continue to be served from operating ground infrastructure.
Abstract: Resilient communication networks, which can continue operations even after a calamity, will be a central feature of future smart cities Recent proliferation of drones propelled by the availability of cheap commodity hardware presents a new avenue for provisioning such networks In particular, with the advent of Google's Sky Bender and Facebook's internet drone, drone empowered small cellular networks (DSCNs) are no longer fantasy DSCNs are attractive solution for public safety networks because of swift deployment capability and intrinsic network reconfigurability While DSCNs have received some attention in the recent past, the design space of such networks has not been extensively traversed In particular, co-existence of such networks with an operational ground cellular network in a post-disaster situation has not been investigated Moreover, design parameters such as optimal altitude and number of drone base stations, etc, as a function of destroyed base stations, propagation conditions, etc, have not been explored In order to address these design issues, we present a comprehensive statistical framework which is developed from stochastic geometric perspective We then employ the developed framework to investigate the impact of several parametric variations on the performance of the DSCNs Without loss of any generality, in this article, the performance metric employed is coverage probability of a down-link mobile user It is demonstrated that by intelligently selecting the number of drones and their corresponding altitudes, ground users coverage can be significantly enhanced This is attained without incurring significant performance penalty to the mobile users which continue to be served from operating ground infrastructure

63 citations

Proceedings ArticleDOI
01 May 2017
TL;DR: The throughput under the proposed scheme can be significantly enhanced when compared to a conventional implementation of 802.11ah, with the help of an analytical framework.
Abstract: IEEE 802.11ah has recently emerged as a promising standard for enabling massive machine-to-machine (M2M) communication. In order to support uplink data transmission from dense machine type clients (such as smart meters, IoT end nodes etc.), 802.11ah relies upon the restricted access window (RAW) based Medium Access Control (MAC) protocol. The underlying motivation behind this protocol is to reduce the contention for spectrum access among a large number of devices. The nodes contend with each other in their assigned RAW slot using Carrier Sense Multiple Access with Collision Avoidance (CSMA/CA). In each RAW slot, the throughput depends upon the number of nodes. Current studies have suggested that the duration of each RAW slot should be the same in the entire RAW frame. However in this paper, we argue that the duration of each RAW slot should be chosen according to the size of the group. We present a model where a RAW frame is divided into two sub-frames and the duration of RAW slots in each sub-frame is chosen according to the size of the group. With the help of an analytical framework, we demonstrate that the throughput under our proposed scheme can be significantly enhanced when compared to a conventional implementation.

49 citations

Journal ArticleDOI
TL;DR: This paper investigates the capability of the eavesdropper to jeopardize the security of the system by mitigating the interfering effect of the artificial noise using zero forcing as a receive beamforming strategy and shows that although zero forcing is not the optimal strategy to maximize the SNR, it offers (from the eaves dropper’s perspective) a better performance than MMSE for MIMO frequency selective channels and thus threatens the overall security ofThe system.

34 citations

Journal ArticleDOI
TL;DR: Close closed-form bounds for the ergodic capacity in Rayleigh fading channels are presented and it is shown that these bounds match perfectly with Monte-Carlo simulations, particularly for moderate and high average signal-to-noise ratio (SNR) of the first hop.
Abstract: Since a closed-form expression for the exact ergodic capacity of dual-hop fixed-gain relay networks is not mathematically tractable, thus we will present tight closed-form bounds for the ergodic capacity in Rayleigh fading channels. First we express the exact ergodic capacity in terms of a Lommel function and a single integral and then we apply integral inequalities to present one upper bound and two lower bounds on the ergodic capacity. We also show that our closed-form bounds match perfectly with Monte-Carlo simulations, particularly for moderate and high average signal-to-noise ratio (SNR) of the first hop.

32 citations

Journal ArticleDOI
TL;DR: This article unifies the convergence of energy harvesting, cognitive spectrum access and mobile cloud computing technologies into a CIoT architecture which provides a flexible, dynamic, scalable and robust network design road-map for large scale IoT deployment.
Abstract: In this article, we present a unified perspective on the cognitive internet of things (CIoT) It is noted that within the CIoT design we observe the convergence of energy harvesting, cognitive spectrum access and mobile cloud computing technologies We unify these distinct technologies into a CIoT architecture which provides a flexible, dynamic, scalable and robust network design road-map for large scale IoT deployment Since the prime objective of the CIoT network is to ensure connectivity between things, we identify key metrics which characterize the network design space We revisit the definition of cognition in the context of IoT networks and argue that both the energy efficiency and the spectrum efficiency are key design constraints To this end, we define a new performance metric called the `overall link success probability' which encapsulates these constraints The overall link success probability is characterized by both the self-sustainablitiy of the link through energy harvesting and the availability of spectrum for transmissions With the help of a reference scenario, we demonstrate that well-known tools from stochastic geometry can be employed to investigate both the node and the network level performance In particular, the reference scenario considers a large scale deployment of a CIoT network empowered by solar energy harvesting deployed along with the centralized CIoT device coordinators It is assumed that CIoT network is underlaid with a cellular network, ie, CIoT nodes share spectrum with mobile users subject to a certain co-existence constraint Considering the dynamics of both energy harvesting and spectrum sharing, the overall link success probability is then quantified It is shown that both the self-sustainability of the link, and the availability of transmission opportunites, are coupled through a common parameter, ie, the node level transmit power Furthermore, provided the co-existence constraint is satisfied, the link level success in the presence of both the inter-network and intra-network interference is an increasing function of the transmit power We demonstrate that the overall link level success probability can be maximized by employing a certain optimal transmit power Characterization of such an optimal operational point is presented Finally, we highlight some of the future directions which can benefit from the analytical framework developed in this paper

31 citations


Cited by
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Journal ArticleDOI

[...]

08 Dec 2001-BMJ
TL;DR: There is, I think, something ethereal about i —the square root of minus one, which seems an odd beast at that time—an intruder hovering on the edge of reality.
Abstract: There is, I think, something ethereal about i —the square root of minus one. I remember first hearing about it at school. It seemed an odd beast at that time—an intruder hovering on the edge of reality. Usually familiarity dulls this sense of the bizarre, but in the case of i it was the reverse: over the years the sense of its surreal nature intensified. It seemed that it was impossible to write mathematics that described the real world in …

33,785 citations

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
TL;DR: This paper overviews the current research efforts on smart radio environments, the enabling technologies to realize them in practice, the need of new communication-theoretic models for their analysis and design, and the long-term and open research issues to be solved towards their massive deployment.
Abstract: Future wireless networks are expected to constitute a distributed intelligent wireless communications, sensing, and computing platform, which will have the challenging requirement of interconnecting the physical and digital worlds in a seamless and sustainable manner. Currently, two main factors prevent wireless network operators from building such networks: (1) the lack of control of the wireless environment, whose impact on the radio waves cannot be customized, and (2) the current operation of wireless radios, which consume a lot of power because new signals are generated whenever data has to be transmitted. In this paper, we challenge the usual “more data needs more power and emission of radio waves” status quo, and motivate that future wireless networks necessitate a smart radio environment: a transformative wireless concept, where the environmental objects are coated with artificial thin films of electromagnetic and reconfigurable material (that are referred to as reconfigurable intelligent meta-surfaces), which are capable of sensing the environment and of applying customized transformations to the radio waves. Smart radio environments have the potential to provide future wireless networks with uninterrupted wireless connectivity, and with the capability of transmitting data without generating new signals but recycling existing radio waves. We will discuss, in particular, two major types of reconfigurable intelligent meta-surfaces applied to wireless networks. The first type of meta-surfaces will be embedded into, e.g., walls, and will be directly controlled by the wireless network operators via a software controller in order to shape the radio waves for, e.g., improving the network coverage. The second type of meta-surfaces will be embedded into objects, e.g., smart t-shirts with sensors for health monitoring, and will backscatter the radio waves generated by cellular base stations in order to report their sensed data to mobile phones. These functionalities will enable wireless network operators to offer new services without the emission of additional radio waves, but by recycling those already existing for other purposes. This paper overviews the current research efforts on smart radio environments, the enabling technologies to realize them in practice, the need of new communication-theoretic models for their analysis and design, and the long-term and open research issues to be solved towards their massive deployment. In a nutshell, this paper is focused on discussing how the availability of reconfigurable intelligent meta-surfaces will allow wireless network operators to redesign common and well-known network communication paradigms.

1,504 citations

Journal ArticleDOI
TL;DR: In this article, a comprehensive tutorial on the potential benefits and applications of UAVs in wireless communications is presented, and the important challenges and the fundamental tradeoffs in UAV-enabled wireless networks are thoroughly investigated.
Abstract: The use of flying platforms such as unmanned aerial vehicles (UAVs), popularly known as drones, is rapidly growing. In particular, with their inherent attributes such as mobility, flexibility, and adaptive altitude, UAVs admit several key potential applications in wireless systems. On the one hand, UAVs can be used as aerial base stations to enhance coverage, capacity, reliability, and energy efficiency of wireless networks. On the other hand, UAVs can operate as flying mobile terminals within a cellular network. Such cellular-connected UAVs can enable several applications ranging from real-time video streaming to item delivery. In this paper, a comprehensive tutorial on the potential benefits and applications of UAVs in wireless communications is presented. Moreover, the important challenges and the fundamental tradeoffs in UAV-enabled wireless networks are thoroughly investigated. In particular, the key UAV challenges such as 3D deployment, performance analysis, channel modeling, and energy efficiency are explored along with representative results. Then, open problems and potential research directions pertaining to UAV communications are introduced. Finally, various analytical frameworks and mathematical tools, such as optimization theory, machine learning, stochastic geometry, transport theory, and game theory are described. The use of such tools for addressing unique UAV problems is also presented. In a nutshell, this tutorial provides key guidelines on how to analyze, optimize, and design UAV-based wireless communication systems.

1,395 citations

Posted Content
TL;DR: This tutorial provides key guidelines on how to analyze, optimize, and design UAV-based wireless communication systems on the basis of 3D deployment, performance analysis, channel modeling, and energy efficiency.
Abstract: The use of flying platforms such as unmanned aerial vehicles (UAVs), popularly known as drones, is rapidly growing. In particular, with their inherent attributes such as mobility, flexibility, and adaptive altitude, UAVs admit several key potential applications in wireless systems. On the one hand, UAVs can be used as aerial base stations to enhance coverage, capacity, reliability, and energy efficiency of wireless networks. On the other hand, UAVs can operate as flying mobile terminals within a cellular network. Such cellular-connected UAVs can enable several applications ranging from real-time video streaming to item delivery. In this paper, a comprehensive tutorial on the potential benefits and applications of UAVs in wireless communications is presented. Moreover, the important challenges and the fundamental tradeoffs in UAV-enabled wireless networks are thoroughly investigated. In particular, the key UAV challenges such as three-dimensional deployment, performance analysis, channel modeling, and energy efficiency are explored along with representative results. Then, open problems and potential research directions pertaining to UAV communications are introduced. Finally, various analytical frameworks and mathematical tools such as optimization theory, machine learning, stochastic geometry, transport theory, and game theory are described. The use of such tools for addressing unique UAV problems is also presented. In a nutshell, this tutorial provides key guidelines on how to analyze, optimize, and design UAV-based wireless communication systems.

1,071 citations