Indoor wireless communications and applications

Chapter 3 addresses challenges in radio link and system design in indoor scenarios. Given the fact that most human activities take place in indoor environments, the need for supporting ubiquitous indoor data connectivity and location/tracking service becomes even more important than in the previous decades. Specific technical challenges addressed in this section are(i), modelling complex indoor radio channels for effective antenna deployment, (ii), potential of millimeter-wave (mm-wave) radios for supporting higher data rates, and (iii), feasible indoor localisation and tracking techniques, which are summarised in three dedicated sections of this chapter

Diffraction Analysis with UWB Validation for ToA Ranging in the Proximity of Human Body and Metallic Objects

The time-of-arrival (ToA)-based localization technique performs superior in line-of-sight (LoS) conditions, and its accuracy degrades drastically in proximity of micro-metals and human body, when LoS conditions are not met. This calls for modeling and formulation of Direct Path (DP) to help with mitigation of ranging error. However, the current propagation tools and models are mainly designed for telecommunication applications via focus on delay spread of wireless channel profile, whereas ToA-based localization strive for modeling of DP component. This thesis provides a mitigation to the limitation of existing propagation tools and models to computationally capture the effects of micro-metals and human body on ToA-based indoor localization. Solutions for each computational technique are validated by empirical measurements using Ultra-Wide-Band (UWB) signals. Finite- Difference-Time-Domain (FDTD) numerical method is used to estimate the ranging errors, and a combination of Uniform-Theory-of-Diffraction (UTD) ray theory and geometrical ray optics properties are utilized to model the path-loss and the ToA of the DP obstructed by micro- metals. Analytical UTD ray theory and geometrical ray optics properties are exploited to model the path-loss and the ToA of the first path obstructed by the human body for the scattering scenarios. The proposed scattering solution expanded to analytically model the path-loss and ToA of the DP obstructed by human body in angular motion for the radiation scenarios

Potentials of Deterministic Radio Propagation Simulation for AI-Enabled Localization and Sensing

Machine leaning (ML) and artificial intelligence (AI) enable new methods for localization and sensing in next-generation networks to fulfill a wide range of use cases. These approaches rely on learning approaches that require large amounts of training and validation data. This paper addresses the data generation bottleneck to develop and validate such methods by proposing an integrated toolchain based on deterministic channel modeling and radio propagation simulation. The toolchain is demonstrated exemplary for scenario classification to obtain localization-related channel parameters within an aircraft cabin environment

Location-dependent information extraction for positioning

This paper presents an overview of current research investigations within the WHERE-2 Project with respect to location-dependent information extraction and how this information can be used towards the benefit of positioning. It is split into two main sections; the first one relies on non-radio means such as inertial sensors and prior knowledge about the environment geometry, which can be used in the form of map constraints to improve user positioning precision in indoor environments. The second section presents how location-specific radio information can be exploited in a more sophisticated way into advanced positioning algorithms. The intended solutions include exploitation of the slow fading dynamics in addition to the fast-fading parameters, adaptation of the system to its environment on both network and terminal sides and also how specific environmental properties such as the dielectric wall parameters can be extracted and thereafter used for more accurate fingerprinting database generation using Ray Tracing modelling methods. Most of the techniques presented herein rely on real-life measurements or experiments

Ray-Based Statistical Propagation Modeling for Indoor Corridor Scenarios at 15 GHz

According to the demands for fifth-generation (5G) communication systems, high frequency bands (above 6 GHz) need to be adopted to provide additional spectrum. This paper investigates the characteristics of indoor corridor channels at 15 GHz. Channel measurements with a vector network analyzer in two corridors were conducted. Based on a ray-optical approach, a deterministic channel model covering both antenna and propagation characteristic is presented. The channel model is evaluated by comparing simulated results of received power and root mean square delay spread with the corresponding measurements. By removing the impact of directional antennas from the transmitter and receiver, a path loss model as well as small-scale fading properties for typical corridors is presented based on the generated samples from the deterministic model. Results show that the standard deviation of path loss variation is related to the Tx height, and placing the Tx closer to the ceiling leads to a smaller fluctuation of path loss

Cooperative Radio Communications for Green Smart Environments

The demand for mobile connectivity is continuously increasing, and by 2020 Mobile and Wireless Communications will serve not only very dense populations of mobile phones and nomadic computers, but also the expected multiplicity of devices and sensors located in machines, vehicles, health systems and city infrastructures. Future Mobile Networks are then faced with many new scenarios and use cases, which will load the networks with different data traffic patterns, in new or shared spectrum bands, creating new specific requirements. This book addresses both the techniques to model, analyse and optimise the radio links and transmission systems in such scenarios, together with the most advanced radio access, resource management and mobile networking technologies. This text summarises the work performed by more than 500 researchers from more than 120 institutions in Europe, America and Asia, from both academia and industries, within the framework of the COST IC1004 Action on "Cooperative Radio Communications for Green and Smart Environments". The book will have appeal to graduates and researchers in the Radio Communications area, and also to engineers working in the Wireless industry. Topics discussed in this book include: • Radio waves propagation phenomena in diverse urban, indoor, vehicular and body environments• Measurements, characterization, and modelling of radio channels beyond 4G networks• Key issues in Vehicle (V2X) communication• Wireless Body Area Networks, including specific Radio Channel Models for WBANs• Energy efficiency and resource management enhancements in Radio Access Networks• Definitions and models for the virtualised and cloud RAN architectures• Advances on feasible indoor localization and tracking techniques• Recent findings and innovations in antenna systems for communications• Physical Layer Network Coding for next generation wireless systems• Methods and techniques for MIMO Over the Air (OTA) testin