9 research outputs found
System Level Design of Software-Defined Radio Platform
This major qualifying project proposes a new single-board design for a Dedicated Short Range Communication (DSRC) On Board Unit (OBU) which consists of a Zynq 7030 system on a chip and AD9361 wideband transceiver. This software-defined radio (SDR) platform design is based on ZedBoard and FMcomms2. The advantages of this approach compared to the ZedBoard and FMcomms2 joint solution are smaller form factor, front end tuned to 5.9GHz and a more powerful processor. Since the prototype has not been manufactured due to the time constraints of this project, the working implementation of 6GHz DSRC radio 802.11p in GNU Radio has been confirmed on the lower capability hardware USRP2 and USRP N210 (Universal Software Radio Peripheral)
New strategies for low noise, agile PLL frequency synthesis
Phase-Locked Loop based frequency synthesis is an essential technique employed in wireless communication systems for local oscillator generation. The ultimate goal in any design of frequency synthesisers is to generate precise and stable output frequencies with fast switching and minimal spurious and phase noise. The conflict between high resolution and fast switching leads to two separate integer synthesisers to satisfy critical system requirements.
This thesis concerns a new sigma-delta fractional-N synthesiser design which is able to be directly modulated at high data rates while simultaneously achieving good noise performance. Measured results from a prototype indicate that fast switching, low noise and spurious free spectra are achieved for most covered frequencies. The phase noise of the unmodulated synthesiser was measured −113 dBc/Hz at 100 kHz offset from the carrier.
The intermodulation effect in synthesisers is capable of producing a family of spurious components of identical form to fractional spurs caused in quantisation process. This effect directly introduces high spurs on some channels of the synthesiser output. Numerical and analytic results describing this effect are presented and amplitude and distribution of the resulting fractional spurs are predicted and validated against simulated and measured results. Finally an experimental arrangement, based on a phase compensation technique, is presented demonstrating significant suppression of intermodulation-borne spurs.
A new technique, pre-distortion noise shaping, is proposed to dramatically reduce the impact of fractional spurs in fractional-N synthesisers. The key innovation is the introduction in the bitstream generation process of carefully-chosen set of components at identical offset frequencies and amplitudes and in anti-phase with the principal fractional spurs. These signals are used to modify the Σ-Δ noise shaping, so that fractional spurs are effectively cancelled. This approach can be highly effective in improving spectral purity and reduction of spurious components caused by the Σ-Δ modulator, quantisation noise, intermodulation effects and any other circuit factors. The spur cancellation is achieved in the digital part of the synthesiser without introducing additional circuitry. This technique has been convincingly demonstrated by simulated and experimental results
Analysis, characterization and optimization of the energy efficiency on softwarized mobile platforms
Mención Internacional en el título de doctorLa inminente 5ª generación de sistemas móviles (5G) está a punto de revolucionar la industria, trayendo una nueva arquitectura orientada a los nuevos mercados verticales y servicios. Debido a esto, el 5G Infrastructure Public Private Partnership (5G-PPP) ha especificado una lista de Indicadores de Rendimiento Clave (KPI) que todo sistema 5G tiene que soportar, por ejemplo incrementar por 1000 el volumen de datos, de 10 a 100 veces m´as dispositivos conectados o consumos energéticos 10 veces inferiores. Con el fin de conseguir estos requisitos, se espera expandir los despligues actuales usando mas Puntos de Acceso (PoA) incrementando así su densidad con
múltiples tecnologías inalámbricas. Esta estrategia de despliegue masivo tiene una contrapartida en la eficiencia energética, generando un conflicto con el KPI de reducir por 10 el consumo energético. En este contexto, la comunidad investigadora ha propuesto nuevos paradigmas para alcanzar los requisitos impuestos para los sistemas 5G, siendo materializados en tecnologías como Redes Definidas por Software (SDN) y Virtualización de Funciones de Red (NFV). Estos nuevos paradigmas son el primer paso hacia la softwarización de los despliegues móviles, incorporando nuevos grados de flexibilidad y reconfigurabilidad de la Red de Acceso Radio (RAN). En esta tesis, presentamos primero un análisis detallado y caracterización de las redes móviles softwarizadas. Consideramos el software como la base de la nueva generación de redes celulares y, por lo tanto, analizaremos y caracterizaremos el impacto en la eficiencia energética de estos
sistemas. La primera meta de este trabajo es caracterizar las plataformas software disponibles para Radios Definidas por Software (SDR), centrándonos en las dos soluciones principales de código abierto: OpenAirInterface (OAI) y srsLTE. Como resultado, proveemos una metodología para analizar y caracterizar el rendimiento de estas soluciones en función del uso de la CPU, rendimiento de red, compatibilidad y extensibilidad de dicho software. Una vez hemos entendido
qué rendimiento podemos esperar de este tipo de soluciones, estudiamos un prototipo SDR construido con aceleración hardware, que emplea una plataformas basada en FPGA. Este prototipo está diseñado para incluir capacidad de ser consciente de la energía, permiento al sistema ser reconfigurado para minimizar la huella energética cuando sea posible. Con el fin de validar el diseño de nuestro sistema, más tarde presentamos una plataforma para caracterizar la energía que será empleada para medir experimentalmente el consumo energético de dispositivos reales. En nuestro enfoque, realizamos dos tipos de análisis: a pequeña escala de tiempo y a gran escala de tiempo. Por lo tanto, para validar nuestro entorno de medidas, caracterizamos a través de análisis numérico los algoritmos para la Adaptación de la Tasa (RA) en IEEE 802.11, para entonces comparar
nuestros resultados teóricos con los experimentales. A continuación extendemos nuestro
análisis a la plataforma SDR acelerada por hardware previamente mencionada. Nuestros resultados experimentales muestran que nuestra sistema puede en efecto reducir la huella energética reconfigurando el despligue del sistema.
Entonces, la escala de tiempos es elevada y presentamos los esquemas para Recursos bajo Demanda (RoD) en despliegues de red ultra-densos. Esta estrategia está basada en apagar/encender
dinámicamente los elementos que forman la red con el fin de reducir el total del consumo
energético. Por lo tanto, presentamos un modelo analítico en dos sabores, un modelo exacto que predice el comportamiento del sistema con precisión pero con un alto coste computacional y uno simplificado que es más ligero en complejidad mientras que mantiene la precisión. Nuestros resultados muestran que estos esquemas pueden efectivamente mejorar la eficiencia energética de
los despliegues y mantener la Calidad de Servicio (QoS). Con el fin de probar la plausibilidad
de los esquemas RoD, presentamos un plataforma softwarizada que sigue el paradigma SDN,
OFTEN (OpenFlow framework for Traffic Engineering in mobile Network with energy awareness).
Nuestro diseño está basado en OpenFlow con funcionalidades para hacerlo consciente de
la energía. Finalmente, un prototipo real con esta plataforma es presentando, probando así la plausibilidad de los RoD en despligues reales.The upcoming 5th Generation of mobile systems (5G) is about to revolutionize the industry,
bringing a new architecture oriented to new vertical markets and services. Due to this, the 5G-PPP
has specified a list of Key Performance Indicator (KPI) that 5G systems need to support e.g. increasing
the 1000 times higher data volume, 10 to 100 times more connected devices or 10 times
lower power consumption. In order to achieve these requirements, it is expected to expand the
current deployments using more Points of Attachment (PoA) by increasing their density and by
using multiple wireless technologies. This massive deployment strategy triggers a side effect in
the energy efficiency though, generating a conflict with the “10 times lower power consumption”
KPI. In this context, the research community has proposed novel paradigms to achieve the imposed
requirements for 5G systems, being materialized in technologies such as Software Defined
Networking (SDN) and Network Function Virtualization (NFV). These new paradigms are the
first step to softwarize the mobile network deployments, enabling new degrees of flexibility and
reconfigurability of the Radio Access Network (RAN).
In this thesis, we first present a detailed analysis and characterization of softwarized mobile
networking. We consider software as a basis for the next generation of cellular networks and
hence, we analyze and characterize the impact on the energy efficiency of these systems. The
first goal of this work is to characterize the available software platforms for Software Defined
Radio (SDR), focusing on the two main open source solutions: OAI and srsLTE. As result, we
provide a methodology to analyze and characterize the performance of these solutions in terms
of CPU usage, network performance, compatibility and extensibility of the software. Once we
have understood the expected performance for such platformsc, we study an SDR prototype built
with hardware acceleration, that employs a FPGA based platform. This prototype is designed
to include energy-awareness capabilites, allowing the system to be reconfigured to minimize the
energy footprint when possible. In order to validate our system design, we later present an energy
characterization platform that we will employ to experimentally measure the energy consumption
of real devices. In our approach, we perform two kind of analysis: at short time scale and large
time scale. Thus, to validate our approach in short time scale and the energy framework, we have
characterized though numerical analysis the Rate Adaptation (RA) algorithms in IEEE 802.11,
and then compare our theoretical results to the obtained ones through experimentation. Next
we extend our analysis to the hardware accelerated SDR prototype previously mentioned. Our experimental results show that our system can indeed reduce the energy footprint reconfiguring
the system deployment.
Then, the time scale of our analysis is elevated and we present Resource-on-Demand (RoD)
schemes for ultradense network deployments. This strategy is based on dynamically switch on/off
the elements that form the network to reduce the overall energy consumption. Hence, we present
a analytic model in two flavors, an exact model that accurately predicts the system behaviour
but high computational cost and a simplified one that is lighter in complexity while keeping the
accuracy. Our results show that these schemes can effectively enhance the energy efficiency of
the deployments and mantaining the Quality of Service (QoS). In order to prove the feasibility of
RoD, we present a softwarized platform that follows the SDN paradigm, the OFTEN (Open Flow
framework for Traffic Engineering in mobile Networks with energy awareness) framework. Our
design is based on OpenFlow with energy-awareness functionalities. Finally, a real prototype of
this framework is presented, proving the feasibility of the RoD in real deployments.FP7-CROWD (2013-2015) CROWD (Connectivity management for eneRgy Optimised Wireless Dense networks).-- H2020-Flex5GWare (2015-2017) Flex5GWare (Flexible and efficient hardware/software platforms for 5G network elements and devices).Programa de Doctorado en Ingeniería Telemática por la Universidad Carlos III de MadridPresidente: Gramaglia , Marco.- Secretario: José Nuñez.- Vocal: Fabrizio Giulian
A fast-locking agile frequency synthesizer for MIMO dual-mode WiFi/WiMAX applications
In this paper, a wide-range and fast-locking phase-locked loop (PLL) frequency synthesizer using the band selection technique for the agile voltage-controlled oscillator (VCO) is proposed. The minimum time for band selection, discretely tuned by a time-to-voltage converter, can reach four times of the reference period. In addition, a current-enhanced circuit applied to the PLL can make settling behavior faster. The synthesizer is implemented in a 0.13-mu m CMOS process, which provides the range from 4.6 GHz to 5.4 GHz with the phase noise of -106 dBc/Hz at 1-MHz offset. Combining the fast-locking techniques, the lock time of the synthesizer can be less than 13.2 mu s and consume 39 mW from a 1.2-V power supply
Shortest Route at Dynamic Location with Node Combination-Dijkstra Algorithm
Abstract— Online transportation has become a basic
requirement of the general public in support of all activities to go
to work, school or vacation to the sights. Public transportation
services compete to provide the best service so that consumers
feel comfortable using the services offered, so that all activities
are noticed, one of them is the search for the shortest route in
picking the buyer or delivering to the destination. Node
Combination method can minimize memory usage and this
methode is more optimal when compared to A* and Ant Colony
in the shortest route search like Dijkstra algorithm, but can’t
store the history node that has been passed. Therefore, using
node combination algorithm is very good in searching the
shortest distance is not the shortest route. This paper is
structured to modify the node combination algorithm to solve the
problem of finding the shortest route at the dynamic location
obtained from the transport fleet by displaying the nodes that
have the shortest distance and will be implemented in the
geographic information system in the form of map to facilitate
the use of the system.
Keywords— Shortest Path, Algorithm Dijkstra, Node
Combination, Dynamic Location (key words
Naval Postgraduate School Catalog 2015
Approved for public release; distribution is unlimited
Naval Postgraduate School Catalog 2016
Approved for public release; distribution is unlimited