115 research outputs found
A real-time FPGA-based implementation of a high-performance MIMO-OFDM mobile WiMAX transmitter
The Multiple Input Multiple Output (MIMO)-Orthogonal
Frequency Division Multiplexing (OFDM) is considered a key technology
in modern wireless-access communication systems. The IEEE 802.16e
standard, also denoted as mobile WiMAX, utilizes the MIMO-OFDM
technology and it was one of the first initiatives towards the roadmap of
fourth generation systems. This paper presents the PHY-layer design, implementation
and validation of a high-performance real-time 2x2 MIMO
mobile WiMAX transmitter that accounts for low-level deployment issues
and signal impairments. The focus is mainly laid on the impact of
the selected high bandwidth, which scales the implementation complexity
of the baseband signal processing algorithms. The latter also requires
an advanced pipelined memory architecture to timely address the datapath
operations that involve high memory utilization. We present in this
paper a first evaluation of the extracted results that demonstrate the
performance of the system using a 2x2 MIMO channel emulation.Postprint (published version
Rapid Prototyping for Evaluating Vehicular Communications
[Abstract] This Thesis details the different elements of a rapid prototyping system able to
implement and evaluate vehicular communications fast, according to the continuously
evolving requirements of the industry. The system is basically composed of a testbed
and a channel emulator, which allow evaluating communication transceivers in realistic
vehicular scenarios.
Two different testbeds are introduced: a generic 2x2 system and a vehicular platform.
The former is used to compare and study space-time block coding (STBC) transmissions
at 2.4 GHz over different indoor channels. The latter makes use of software
transceivers whose performance is evaluated when they work under artificial high-speed
Rayleigh-fading scenarios.
To show the capabilities of both platforms, three software transceivers have been
developed following the specifications for the physical layers of the standards IEEE
802.11p, IEEE 802.11a and IEEE 802.16e (Mobile WiMAX). The present work details
the different elements that make up each transceiver and indicates how to connect them
to the rest of the system to perform evaluation measurements.
Finally, single-antenna and multi-antenna performances are measured thanks to the
design and implementation of three FPGA-based channel emulators that are able to
recreate up to seven different vehicular scenarios that include urban canyons, suburban
areas and highways[Resumo] A presente Tese detalla os elementos necesarios para constituir un sistema basado en
prototipado rápido capaz de levar a cabo e avaliar comunicacións vehiculares. O hardware
do sistema está composto básicamente por unha plataforma de probas (testbed)
e un emulador de canal, os cales permiten avaliar o rendemento de transceptores
inartiamicos recreando diferentes escenarios vehiculares.
Inicialmente, este traballo céntrase na descripción do hardware do sistema, detallando
a construcción e proba dunha plataforma multi-antena e un testebed vehicular.
Estos sistemas permitiron, respectivamente, estudar o comportamento de códigos STBC
(space-time block codes) en interiores e medir o rendemento de tranceptores software
ao traballar a distintas velocidades vehiculares en canais con desvaecemento Rayleigh.
Tres transceptores software foron creados seguindo as especificacións das capas
físicas dos estándares IEEE 802.11p, IEEE 802.11a e IEEE 802.16e (Mobile WiMAX).
Este traballo detalla os diferentes componentes de cada transceptor, indicando cómo
conectalos ao resto do sistema para realizar a avaliacition do seu rendemento. Dita
avaliación realizouse coa axuda de tres emuladores de canal basados en tecnoloxía
FPGA (Field Programmable Gate Array), os cales son capaces de recrear ata sete
escenarios vehiculares distintos, incluindo cañóns urbanos, zonas suburbanas e autopistas.[Resumen] La presente Tesis detalla los elementos necesarios para constituir un sistema basado
en prototipado rtiapido capaz de llevar a cabo y evaluar comunicaciones vehiculares.
El hardware del sistema está compuesto por una plataforma de pruebas (testbed) y
un emulador de canal, los cuales permiten evaluar el rendimiento de transceptores
inaltiambricos recreando diferentes escenarios vehiculares.
Inicialmente, este trabajo se centra en la descripcition del hardware del sistema,
detallando la construccition y prueba de una plataforma multi-antena y un testebed
vehicular. Estos sistemas han permitido, respectivamente, estudiar el comportamiento
de ctiodigos STBC (space-time block codes) en interiores y medir el rendimiento en
canal con desvanecimiento Rayleigh de tranceptores software a distintas velocidades
vehiculares.
Tres transceptores software han sido creados siguiendo las especificaciones de las
capas físicas de los estandares IEEE 802.11p, IEEE 802.11a e IEEE 802.16e (Mobile
WiMAX). Este trabajo detalla los diferentes componentes de cada transceptor,
indicando ctiomo conectarlos al resto del sistema para realizar la evaluacition de su
rendimiento. Dicha evaluacition se realiztio con la ayuda de tres emuladores de canal
basados en FPGAs (Field Programmable Gate Array), los cuales son capaces de recrear
comunicaciones multi-antena en hasta siete escenarios vehiculares distintos, incluyendo
cañones urbanos, zonas suburbanas y autopistas
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