Optimal Power Allocation for Integrated Visible Light Positioning and Communication System with a Single LED-Lamp

In this paper, we investigate an integrated visible light positioning and communication (VLPC) system with a single LED-lamp. First, by leveraging the fact that the VLC channel model is a function of the receiver's location, we propose a system model that estimates the channel state information (CSI) based on the positioning information without transmitting pilot sequences. Second, we derive the Cramer-Rao lower bound (CRLB) on the positioning error variance and a lower bound on the achievable rate with on-off keying modulation. Third, based on the derived performance metrics, we optimize the power allocation to minimize the CRLB, while satisfying the rate outage probability constraint. To tackle this non-convex optimization problem, we apply the worst-case distribution of the Conditional Value-at-Risk (CVaR) and the block coordinate descent (BCD) methods to obtain the feasible solutions. Finally, the effects of critical system parameters, such as outage probability, rate threshold, total power threshold, are revealed by numerical results.Comment: 13 pages, 14 figures, accepted by IEEE Transactions on Communication

An Intelligent Management System for Hybrid Network between Visible Light Communication and Radio Frequency

This thesis investigates the challenges and potential solutions associated with hybrid Visible Light Communication (VLC) and Radio Frequency (RF) systems for indoor network environments. The rapid development of VLC technology, characterized by its high data rates, energy efficiency, and inherent security features, offers promising opportunities to complement RF networks in providing seamless connectivity and improved performance. However, integrating VLC and RF technologies effectively requires addressing a range of research and engineering challenges, including network coexistence, handover mechanisms, resource allocation, localization, and standardization.We begin by conducting a comprehensive literature review encompassing existing research, technologies, and solutions related to hybrid VLC/RF architectures, handover management, indoor localization techniques, and the challenges faced by these systems. This background provides a solid foundation for understanding the current state-of-the-art and identifying research gaps in the field of hybrid VLC/RF networks.Next, we propose a novel hybrid network architecture that integrates VLC and RF communication systems to enhance their strengths while mitigating their weaknesses. We discuss various types of hybrid VLC/RF architectures found in the literature and present our proposed design, which addresses the identified challenges through innovative strategies and mechanisms.To improve system performance in our hybrid system, we develop an enhanced priority feedback channel that optimizes the traffic priority based on user preferences and network conditions. This approach minimizes service disruptions, reduces latency, and maintains user Quality of Experience (QoE)\nomenclature{QoE}{Quality of Experience}.Furthermore, we introduce a novel intelligent management system architecture tailored for hybrid VLC/RF networks. This system employs advanced algorithms and techniques to optimize resource allocation, load balancing, localization, and handover management, ensuring efficient operation and seamless connectivity.We evaluate the performance of our proposed solutions through extensive simulations and testbed experiments, considering different network scenarios and metrics. The results demonstrate significant improvements in terms of data rate, latency, handover success rate, and localization accuracy, validating the effectiveness of our proposed architecture and management system.Lastly, we explore several real-world applications and case studies of our intelligent management system in various indoor environments, such as retail stores, offices, and hospitals. These examples illustrate the practical benefits of our solution in enhancing customer experiences, optimizing operational efficiency, facilitating targeted marketing, and improving energy management.In conclusion, this thesis contributes to the advancement of hybrid VLC/RF networks by proposing an innovative architecture and intelligent management system that address the key challenges faced by these systems in indoor environments. The findings and solutions presented in this work provided the backbone for the future research and development efforts aimed at fully harnessing the potential of VLC technology in combination with RF networks

Robust Power Allocation for Integrated Visible Light Positioning and Communication Networks

Integrated visible light positioning and communication (VLPC), capable of combining advantages of visible light communications (VLC) and visible light positioning (VLP), is a promising key technology for the future Internet of Things. In VLPC networks, positioning and communications are inherently coupled, which has not been sufficiently explored in the literature. We propose a robust power allocation scheme for integrated VLPC Networks by exploiting the intrinsic relationship between positioning and communications. Specifically, we derive explicit relationships between random positioning errors, following both a Gaussian distribution and an arbitrary distribution, and channel state information errors. Then, we minimize the Cramer-Rao lower bound (CRLB) of positioning errors, subject to the rate outage constraint and the power constraints, which is a chance-constrained optimization problem and generally computationally intractable. To circumvent the nonconvex challenge, we conservatively transform the chance constraints to deterministic forms by using the Bernstein-type inequality and the conditional value-at-risk for the Gaussian and arbitrary distributed positioning errors, respectively, and then approximate them as convex semidefinite programs. Finally, simulation results verify the robustness and effectiveness of our proposed integrated VLPC design schemes.Comment: 13 pages, 15 figures, accepted by IEEE Transactions on Communication

Five Facets of 6G: Research Challenges and Opportunities

Whilst the fifth-generation (5G) systems are being rolled out across the globe, researchers have turned their attention to the exploration of radical next-generation solutions. At this early evolutionary stage we survey five main research facets of this field, namely {\em Facet~1: next-generation architectures, spectrum and services, Facet~2: next-generation networking, Facet~3: Internet of Things (IoT), Facet~4: wireless positioning and sensing, as well as Facet~5: applications of deep learning in 6G networks.} In this paper, we have provided a critical appraisal of the literature of promising techniques ranging from the associated architectures, networking, applications as well as designs. We have portrayed a plethora of heterogeneous architectures relying on cooperative hybrid networks supported by diverse access and transmission mechanisms. The vulnerabilities of these techniques are also addressed and carefully considered for highlighting the most of promising future research directions. Additionally, we have listed a rich suite of learning-driven optimization techniques. We conclude by observing the evolutionary paradigm-shift that has taken place from pure single-component bandwidth-efficiency, power-efficiency or delay-optimization towards multi-component designs, as exemplified by the twin-component ultra-reliable low-latency mode of the 5G system. We advocate a further evolutionary step towards multi-component Pareto optimization, which requires the exploration of the entire Pareto front of all optiomal solutions, where none of the components of the objective function may be improved without degrading at least one of the other components

Introduction to indoor networking concepts and challenges in LiFi

LiFi is networked, bidirectional wireless communication with light. It is used to connect fixed and mobile devices at very high data rates by harnessing the visible light and infrared spectrum. Combined, these spectral resources are 2600 times larger than the entire radio frequency (RF) spectrum. This paper provides the motivation behind why LiFi is a very timely technology, especially for 6th generation (6G) cellular communications. It discusses and reviews essential networking technologies, such as interference mitigation and hybrid LiFi/Wi-Fi networking topologies. We also consider the seamless integration of LiFi into existing wireless networks to form heterogeneous networks across the optical and RF domains and discuss implications and solutions in terms of load balancing. Finally, we provide the results of a real-world hybrid LiFi/Wi-Fi network deployment in a software defined networking testbed. In addition, results from a LiFi deployment in a school classroom are provided, which show that Wi-Fi network performance can be improved significantly by offloading traffic to the LiFi

Light-Fidelity as Next Generation Network Technology: A Bibliometric Survey and Analysis

This paper delivers a systematic review and a bibliometric survey analysis of Light-Fidelity (Li-Fi) indoor implementation in Next Generation Network (NGN). The main objective of this study is to design a communication network based on NGN-Li-Fi for the indoor implementation which aims to increase user Quality of Service (QoS). The main merits and contributions of this study are the thorough and detailed analysis of the review, both in literature surveys and bibliometric analysis, as well as the discussion of the implementation model challenges of Li-Fi in both indoor and outdoor environments. The issue articulated in an indoor communication network is the possibility of intermittent connectivity due to barriers caused by line-of-sight (LOS) between the LED transmitter and receiver, handover due to channel overlap, and other network reliability issues. To realize the full potential and significant benefits of the Next Generation Network, challenges in indoor communication such as load-balancing and anticipating network congestion (traffic congestion) must be addressed. The main benefit of this study is the in-depth investigation of surveys in both selected critical literatures and bibliometric approach. This study seeks to comprehend the implications of Next Generation networks for indoor communication networks, particularly for visible light communication channels