Timing and Carrier Synchronization in Wireless Communication Systems: A Survey and Classification of Research in the Last 5 Years

Timing and carrier synchronization is a fundamental requirement for any wireless communication system to work properly. Timing synchronization is the process by which a receiver node determines the correct instants of time at which to sample the incoming signal. Carrier synchronization is the process by which a receiver adapts the frequency and phase of its local carrier oscillator with those of the received signal. In this paper, we survey the literature over the last 5 years (2010–2014) and present a comprehensive literature review and classification of the recent research progress in achieving timing and carrier synchronization in single-input single-output (SISO), multiple-input multiple-output (MIMO), cooperative relaying, and multiuser/multicell interference networks. Considering both single-carrier and multi-carrier communication systems, we survey and categorize the timing and carrier synchronization techniques proposed for the different communication systems focusing on the system model assumptions for synchronization, the synchronization challenges, and the state-of-the-art synchronization solutions and their limitations. Finally, we envision some future research directions

Measurement and Optimization of LTE Performance

4G Long Term Evolution (LTE) mobile system is the fourth generation communication system adopted worldwide to provide high-speed data connections and high-quality voice calls. Given the recent deployment by mobile service providers, unlike GSM and UMTS, LTE can be still considered to be in its early stages and therefore many topics still raise great interest among the international scientific research community: network performance assessment, network optimization, selective scheduling, interference management and coexistence with other communication systems in the unlicensed band, methods to evaluate human exposure to electromagnetic radiation are, as a matter of fact, still open issues. In this work techniques adopted to increase LTE radio performances are investigated. One of the most wide-spread solutions proposed by the standard is to implement MIMO techniques and within a few years, to overcome the scarcity of spectrum, LTE network operators will offload data traffic by accessing the unlicensed 5 GHz frequency. Our Research deals with an evaluation of 3GPP standard in a real test best scenario to evaluate network behavior and performance

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

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

Arquitectura de Sistemas de Comunicaciones Tierra-Tierra y Aire-Tierra con Multiplexación Espacial

Tesis (DCI)--FCEFN-UNC, 2017La interacción autómata de múltiples tipos de dispositivos inteligentes (Smart Devices - SD) conforman una red conocida como internet de las cosas (Internet-of-Things - IoT) la cual ofrece potenciales beneficios para incrementar efectivamente la calidad de vida de las personas. Los potenciales beneficios del paradigma de IoT se apoyan en la integración a la red de IoT de todos los SD, a través de redes de comunicaciones entre máquinas (Machine-to-Machine - M2M). Los SD exhiben rango de comunicaciones inalámbricas limitado, debido al bajo costo y consumo de energía impuesto por el paradigma M2M. Consecuentemente, las comunicaciones entre máquinas M2M dependen de alguna infraestructura de comunicaciones, por ejemplo las redes celulares, que otorgue soporte de transporte de datos para dichos dispositivos y así realizar la integración efectiva de todos ellos a la red IoT. No obstante, debido al rango de cobertura limitado de los SD no todos ellos pueden integrarse de manera efectiva, como aquellos que operan en zonas urbanas poco frecuentadas por personas y zonas alejadas de la infraestructura de redes celulares, limitando la proyección de funcionamiento óptimo de la red IoT. Como la proyección del volumen de SD operando en simultáneo se vislumbra masivo, la combinación de tecnologías que despliegan múltiples antenas (Multiple-Input Multiple-Output - MIMO) y la diversidad multiusuario (Multi-User Diversity - MUD), inherente a un conjunto masivo de SD, tiene el potencial para brindar solución al rango limitado de cobertura de los SD. En la primera parte de esta Tesis se proponen y analizan aspectos de implementación de distintos receptores multiusuarios operando en una arquitectura de comunicaciones con diversidad en transmisión a lazo cerrado (Closed-Loop Transmit-Diversity - CL-TD) en canales MIMO, conformación de haz lineal (Linear BeamForming - LBF), selección de usuarios en canales MIMO con múltiples usuarios (Multi-User MIMO - MU-MIMO) en base a información de estado del canal en transmisión parcial (Channel State Information at the Transmitter side - CSIT) y operando en enlaces de canal Tierra-Tierra. En base a estos estudios se determinan cuáles son las estrategias de recepción más conveniente para el problema de rango de cobertura de los SD. Por otro lado, para aquellos SD que operan en zonas alejadas de infraestructuras de soporte de comunicaciones, se propone una infraestructura de comunicaciones alternativa a bordo de un vehículo aéreo autónomo no tripulado (Unmanned Aerial Vehicles - UAV). Sin embargo, para evaluar alguna propuesta de arquitectura de comunicaciones es necesario conocer el comportamiento de canal configurado en este tipo de escenario. Dado que en la literatura, los modelos de canal existentes hasta el momento son insuficientes para describir las características de los nuevos escenarios configurados por los UAV (Zonas rurales, urbanas y sub-urbanas) en vuelos de baja altura, otra contribución fundamental de esta Tesis es la propuesta y extensión de un modelo de canal MIMO de tres dimensiones. La misma considera la existencia de la componente con línea de vista (Line-of-Sight - LOS), la componente sin línea de vista (Non Line-of-Sight - NLOS) con distribuciones de dispersores (Scatterers) no-isotrópicos y las características de movilidad en ambos extremos del enlace. En base a esta propuesta de canal se evalúa una arquitectura de comunicaciones con CL-TD para canales MIMO-3D, LBF y mecanismos de selección de usuarios para canales MU-MIMO con CSIT parcial operando en enlaces de canal Aire-Tierra. En base a estos estudios se evalúa el desempeño de la arquitectura para estos nuevos escenarios