Elijah I. Adegoke

Bio: Elijah I. Adegoke is an academic researcher from University of Warwick. The author has contributed to research in topics: GNSS applications & Delay spread. The author has an hindex of 5, co-authored 18 publications receiving 72 citations. Previous affiliations of Elijah I. Adegoke include Loughborough University.

GNSS Vulnerabilities and Existing Solutions: A Review of the Literature

Abstract: This literature review paper focuses on existing vulnerabilities associated with global navigation satellite systems (GNSSs). With respect to the civilian/non encrypted GNSSs, they are employed for proving positioning, navigation and timing (PNT) solutions across a wide range of industries. Some of these include electric power grids, stock exchange systems, cellular communications, agriculture, unmanned aerial systems and intelligent transportation systems. In this survey paper, physical degradations, existing threats and solutions adopted in academia and industry are presented. In regards to GNSS threats, jamming and spoofing attacks as well as detection techniques adopted in the literature are surveyed and summarized. Also discussed are multipath propagation in GNSS and non line-of-sight (NLoS) detection techniques. The review also identifies and discusses open research areas and techniques which can be investigated for the purpose of enhancing the robustness of GNSS.

Characterizing the Indoor Industrial Channel at 3.5GHz for 5G

Abstract: This paper presents the results of a wideband channel measurement campaign carried out in an indoor environment with representative inventory of a factory. The measurements were carried out using a frequency domain channel sounder from 3.4 - 3.8 GHz and the virtual array method was adopted for averaging small-scale fading effects. From the average power delay profile (APDP), parameters for the Saleh-Valenzuela (S-V) model were extracted for line-of-sight (LoS) and non line-of-sight (NLoS) sites. The ray decay from the S-V model increased with cluster delay for all LoS sites and the delay spread for NLoS sites were higher than LoS locations. The NLoS delay spread was also higher than the results obtained at 2.4 GHz for the same measurement locations. The APDPs from both LoS and NLoS sites showed clustering effects with a mean cluster number of 8/7 for LoS/NLoS sites.

Channel Modeling and Over-the-Air Signal Quality at 3.5 GHz for 5G New Radio

Abstract: With the next generation of mobile communication being trialled across the world, 5G New Radio (NR) promises to provide a flexible radio interface that fits a diverse range of use cases. As trials and pilots progress, propagation studies are required that evaluate electromagnetic (EM) propagation effects for 5G NR signals. In this article, 5G NR signals are used to evaluate the over-the-air (OTA) error vector magnitude (EVM) within a line-of-sight (LoS) rural/urban environment. For the same receiver locations, time dispersion and propagation loss were measured via the root mean square (RMS) delay spread and path loss. The transmitter−receiver distance investigated ranged from $\mathrm {60~m}$ to $\mathrm {450~m}$ . From the measurement campaign, the path loss exponent (PLE) using a directional antenna at the receiver was 1.98, and 1.82 with an omnidirectional antenna. The root mean square error (RMSE) of the floating intercept/close-in (FI/CI) models for the path loss was 4.96/4.74 and 3.84/3.23 for directional and omnidirectional receivers. The delay spread using a cross polar configuration showed significant increase and a dependency of the delay spread on the path loss was observed. For the measurement route, the mean delay spread was $\mathrm {24~ns}$ and $\mathrm {35~ns}$ for directional and omnidirectional measurements. With regards to the EVM, 16 and 64-QAM transmissions were robust along the entire route for directional and omnidirectional antennas, whereas 256-QAM worked in locations where there was minimal obstruction to the propagation path. The average EVM (%) for 16, 64 and 256-QAM measured along the route was 4.5/5.3/3.9 and 3.4/4.3/3.6 for omnidirectional and directional antennas. The OTA results also show that using a directional antenna (as the receiver) significantly improves the obtainable signal quality of 5G NR signals and also reduces outages for higher modulation schemes. With the measurement results presented, system designers can design efficient receivers, estimate coverage and adequately provision services using 5G NR on the sub-6 GHz frequency band.

Heterogeneous Wireless Networks: A Survey of Interworking Architectures

Abstract: A vast majority of current wireless cellular networks are deployed using the homogeneous deployment scenario. The homogeneous cellular system is essentially a network base stations and user terminals with standards power level profiles and similar technical characteristics. All base stations in the network are similar and carefully planned for compatibility. This deployment scenario is complex, rigid, and expensive. Hence the need for a more flexible, cost-effective and ubiquitous deployment model capable of broadband delivery. This need informed the advent of heterogeneous networks, which allow for the deployment of non-homogeneous base stations, with the attendant advantage of improved spectral efficiency per unit area. One of the most important features of next generation networks is the roaming possibility of end user equipments across different access networks. The Session Initiation Protocol (SIP) makes this experience achievable, it also describes other different mobility management solutions and compares the suitability of SIP for roaming across General Packet Radio Service (GPRS), Universal Mobile Telecommunication System (UMTS) and wireless Local Area Networks (WLAN). We present in this paper an overview of the various wireless networking implementations vis-a-vis interworking architectures. The paper also discusses the three generic interworking architectures for WLAN 802.11 and 3GPP networks among others.

Micropower energy harvesting

Abstract: More than a decade of research in the field of thermal, motion, vibration and electromagnetic radiation energy harvesting has yielded increasing power output and smaller embodiments. Power management circuits for rectification and DC-DC conversion are becoming able to efficiently convert the power from these energy harvesters. This paper summarizes recent energy harvesting results and their power management circuits.

Vehicle as a resource (VaaR)

Abstract: Intelligent vehicles are considered key enablers for intelligent transportation systems. They are equipped with resources/components to enable services for vehicle occupants, other vehicles on the road, and third-party recipients. In-vehicle sensors, communication modules, and on-board units with computing and storage capabilities allow the intelligent vehicle to work as a mobile service provider of sensing, data storage, computing, cloud, data relaying, infotainment, and localization services. In this article we introduce the concept of Vehicle as a Resource and shed light on the services a vehicle can potentially provide on the road or parked. We anticipate that an intelligent vehicle can be a significant service provider in a variety of situations, including emergency scenarios.

3GPP Standardized 5G Channel Model for IIoT Scenarios: A Survey

Abstract: Industrial Internet of Things (IIoT) is an emerging area that fifth-generation (5G) mobile communication system penetrates industrial manufacturing applications. The indoor factory has larger space and there are a lot of metal machine tools distributed in it, which makes its radio propagation characteristics and corresponding channel models significantly different from those of the indoor office and indoor hotspot. To support the design and the evaluation of the IIoT techniques, the 3rd Generation Partnership Project (3GPP) released the first 5G IIoT standard model in October 2019. In this article, we give a detailed explanation of this IIoT model and compare it with other indoor models. First, we introduce the standardization of 3GPP IIoT channel model and its motivation. Second, four IIoT subscenarios, which are classified according to the clutter density and antenna height, are described. Third, the potential frequency bands of 5G IIoT are summarized. Fourth, the models of channel parameters, including the path loss and the line-of-sight (LOS) probability, the root mean-square (RMS) delay spread, and the angular spread, are given. Among them, the models of path loss and LOS probability take the antenna height and clutter density into consideration. The model of RMS delay spread changes from frequency-dependent to volume-dependent in order to catch the size variation of factories. Finally, two newly added key channel characteristics, dual mobility and absolute time of arrival, which help to describe the robot movement and positioning, are also presented.