Interference Analysis Between Digital Terrestrial Television (DTT) and 4G LTE Mobile Networks in the Digital Dividend Bands

With the introduction of digital terrestrial television (DTT) and the analogue television switch-off, terrestrial broadcast spectrum in the UHF band is being released for mobile communications, in particular for fourth generation (4G) long term evolution (LTE) mobile services. This spectrum is known as digital dividend. An impending problem when deploying 4G LTE mobile networks in the digital dividend bands is that interferences may appear in the adjacent radio frequency channels used for DTT. In this paper, we analyze the adjacent coexistence of DTT and 4G LTE networks in the digital dividend bands at 700 MHz and 800 MHz. A generic framework is adopted such that results can be easily extrapolated to different scenarios and bands. Results are presented as a function of the guard band between technologies, for both LTE uplink and downlink adjacent to the DTT signals, and for fixed outdoor and portable indoor DTT reception. Also, the effect of using anti-LTE filters is studied.This work was supported by the Spectrum Regulator of Colombia ANE (Agencia Nacional del Espectro).Ribadeneira Ramírez, JA.; Martínez, G.; Gómez Barquero, D.; Cardona, N. (2016). Interference Analysis Between Digital Terrestrial Television (DTT) and 4G LTE Mobile Networks in the Digital Dividend Bands. IEEE Transactions on Broadcasting. 62(1):24-34. doi:10.1109/TBC.2015.2492465S243462

PLANIFICACIÓN Y OPTIMIZACIÓN DE REDES DVB-T PARA LA PROVISIÓN DE SERVICIOS LOCALES Y MÓVILES EN COLOMBIA

RESUMEN Actualmente, el estándar dominante a nivel mundial para la transmisión de TV digital Terrestre es DVB-T (Digital Video Broadcasting- Terrestrial). La mayoría de redes desplegadas han sido diseñadas para una alta capacidad de transmisión y en configuración de frecuencia única (SFN por sus siglas en inglés). DVB-T se diseñó para transmisión fija, con una capa física que no presenta la suficiente robustez para prestar servicios en movilidad. Adicionalmente, uno de los problemas de las redes SFN es la transmisión de contenidos locales, ya que todos los transmisores deben emitir el mismo contenido sincronizado en tiempo y frecuencia. En países donde aún no ha sido implementada la red de Televisión Digital Terrestre (TDT) como Colombia, se puede planificar la red haciendo uso de los últimos avances tecnológicos para ofrecer servicios de recepción fija y móvil, definir áreas de contenidos locales o regionales (LSA por sus siglas en inglés) en redes SFN y maximizar el nivel de cobertura en el escenario de despliegue. En este artículo se describen las siguientes soluciones técnicas compatibles con DVB-T para planificar y optimizar las redes TDT y se presentan parte de los resultados obtenidos en la investigación: diversidad de antenas, modulación jerárquica, mecanismos de corrección de errores en capa de aplicación (AL-FEC por sus siglas en inglés), codificación de video escalable SVC, time slicing, componente de transmisión satelital y gap-fillers. Adicionalmente, se describe la metodología de evaluación y validación de cada una de las soluciones propuestas. El artículo aborda temas de investigación que permiten la penetración en nuevos escenarios de recepción y nichos de mercado para la TV digital, y abre la oportunidad de establecer convenios de cooperación internacional entre instituciones colombianas y de países que al día de hoy ya han finalizado con éxito la transición de televisión analógica a digital, como es el caso de España. PALABRAS CLAVES: DVB-T móvil, Modulación jerárquica, Diversidad de antenas, Corrección de errores en capa de aplicación, Áreas de servicio local.  ANALYTICAL SUMMARY Nowadays, the dominant standard for broadcasting Digital Terrestrial Television (DTT) services on the world is DVB-T (Digital Video Broadcasting- Terrestrial). Most of the DVB-T networks deployed have been designed for high capacity transmission and configured in Single Frequency Network (SFN). DVB-T was designed for fixed rooftop reception using a physical layer with low robustness for mobile services. Further, the transmission of Local Services Area (LSA) is one of the disadvantages of SFN networks, because, all transmitters must broadcast the same content synchronized in time and frequency. In countries like Colombia, where the DTT network has not yet deployed is possible to design the future network using the latest technological advances in order to offer fixed and mobile TV services, defining Local Services Areas in SFN network topologies and maximizing the coverage level on the target scenario. This paper describes the follow technical solutions compatible with DVB-T for planning and optimizing the DTT networks and presents some results obtained: antenna diversity, hierarchical modulation, Application Layer Forward Error Correction (AL-FEC), Scalable Video Coding (SVC), time slicing, satellite component and gap-fillers. Additionally, it describes the methodology used to evaluate and validate each of the solutions proposed. The paper addresses issues of research that open news reception scenarios and market niches for digital TV, creating opportunities of international cooperation projects between Columbian institutions and countries that have successfully completed the transition from analog to digital TV, like Spain.  KEYWORDS: Mobile DVB-T, Hierarchical Modulation, Antenna diversity, Application Layer Forward Error Correction, Local Service Area

Adaptive planning of 3G/4G systems using Q-analysis or polyhedral dynamics

In this paper we present a method for use Q-analysis in the initial planning process and later dynamic adaptation for 3G/4G cellular systems that intends to balance load in order to maximize capacity and reduce lost and dropped calls independently of the type of service. We support our proposal on dynamic simulations made with an own developed tool for dynamic simulations of CDMA systems, and show initial results that partially probe our proposed method

Game engines ray-tracing models for indoor channel modeling

This paper investigates the use of a full 3D ray-tracing system based on Game Engine for the prediction of channel parameters in indoor using frequencies lower than usual. We explore the modeling of indoor channel for Digital TV frequencies and analyze the behavior of material on such low frequencies and how the frequencies affect the constitutive parameters of materials in the scenario. Because of the environment used for experimentation, the number of rays is very high and the number of interactions is higher than usual. We show results of the ray tracing model compared with measurements of delay spread at 594MHz

Multiple diffraction shadowing simulation model

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Multi-functional MIMO Communication in Multi-hop Cellular Systems

Abstract In the context of multi-hop cellular communications, user equipment devices (UE) with relaying capabilities provide a virtual infrastructure that can enhance the cell spectral efficiency. UE relays, which are generally transparent to the destination user and lack channel state information, mainly operate in an open-loop mode. Most open-loop transmission techniques for relaying are based on orthogonal space-time block coding (OSTBC), which offers a good trade-off between performance and complexity. In this paper, we consider the concept of multi-functional MIMO transmission, which combines OSTBC with beamforming techniques. This concept is applied to networks with multiple relays, which can offer a high number of antennas to implement multi-functional MIMO techniques. The proposed schemes are shown to reduce the bit error rate of the destination user with respect to a direct transmission from the BS. Furthermore, the multi-functional setup exhibits better performance than conventional OSTBC at high transmission rates

A statistical channel model for on body Area networks in Ultra Wide Band Communications

This paper presents a novel statistical channel model for Ultra Wide Band Communications when On Body Area Networks Environments are considered. Results and Analysis of frequency measurements from 1GHz to 12GHz for body area networks are described. We propose a modified Saleh-Valenzuela statistical channel model considering different assumptions for small scale statistics in the model. Results show that the small scale amplitude follows a log normal distribution, the inter arrival times between multi path components are poisson process; the decay factor, the number of paths and clusters follow exponential distributions. The proposed model can be used for realistic simulations for on body communications in Ultra Wide Band systems. © 2009 IEEE