Channel Sounding for the Masses: Low Complexity GNU 802.11b Channel Impulse Response Estimation

New techniques in cross-layer wireless networks are building demand for ubiquitous channel sounding, that is, the capability to measure channel impulse response (CIR) with any standard wireless network and node. Towards that goal, we present a software-defined IEEE 802.11b receiver and CIR estimation system with little additional computational complexity compared to 802.11b reception alone. The system implementation, using the universal software radio peripheral (USRP) and GNU Radio, is described and compared to previous work. By overcoming computational limitations and performing direct-sequence spread-spectrum (DS-SS) matched filtering on the USRP, we enable high-quality yet inexpensive CIR estimation. We validate the channel sounder and present a drive test campaign which measures hundreds of channels between WiFi access points and an in-vehicle receiver in urban and suburban areas

Low cost radar and sonar using Open Source hardware and software

Includes abstract.Includes bibliographical references (leaves 89-91).The full range of radar types and innovations can be complex and difficult to prototype, especially for institutions that wish to perform a wide range of experiments for low financial cost. Radar and sonar system development can benefit from digital technology that is powerful for research purposes, easy to use, and inexpensive. The purpose of this thesis was the development of a sonar application using the Universal Software Radio Peripheral and the GNU Radio software framework. These are Open Source tools created for the software-defined radio community. These tools provide a powerful yet flexible means to experiment with a wide range of radio frequency applications, using a minimal amount of relatively cheap hardware. In this thesis, these tools were modified from their original telecommunications purpose, to produce a sonar system that could eventually be scaled to a prototype radar system using the same device and software framework

Wireless UAV restraining system

The large growth in the number of UAVs for civil use has been accompanied by an increase in the number of incidents with these devices, causing several problems to the authorities, since sometimes they are used in restricted areas, which may lead to disruption to air traffic and possibly endanger human lives. That increases the need of detection systems, such as radars, which sometimes have a high cost. In this thesis, a Low-cost Software Defined Radio based Frequency Modulated Continuous Wave (FMCW) Radar is developed, for real time target detection. For the software part, GNU Radio is used and for the hardware part, two different SDR platforms are studied, USRP N210 and LimeSDR mini. The software developed on GNU Radio is tested through a series of simulations in order to verify its capacity to obtain the range of the target and also the speed of the target and, real time target detection results for the two different SDR Platforms are presented and compared. The results obtained demonstrate the ability of the developed software to be used as part of a Low-cost Software Defined Radio based FMCW Radar, and also the potential of this system to be used for target detection, as long as the problem of the additional delay created by the SDR platforms used is solved.O grande crescimento do número de UAVs para uso civil tem sido acompanhado por um aumento do número de incidentes com esses dispositivos, causando vários problemas às autoridades, já que por vezes estes são usados em áreas restritas, o que pode levar à interrupção do tráfego aéreo e possivelmente pôr em perigo vidas humanas. Isto aumenta a necessidade de sistemas de detecção, como os radares, que por vezes têm um custo elevado. Nesta tese, é desenvolvido um sistema de Radar Contínuo Modulado na Frequência baseado em plataformas de Rádio Definido por Software (SDR) de baixo Custo, para detecção de alvos em tempo real. Para o desenvolvimento de software, o GNU Radio é usado e para a componente de hardware são estudadas duas plataformas SDR diferentes, USRP N210 e LimeSDR mini. O software desenvolvido no GNU Radio é testado através de uma série de simulações, a fim de verificar a sua capacidade de detecção da distância a que o alvo se encontra e da velocidade a que o alvo se desloca, e os resultados da detecção de alvos em tempo real para as duas diferentes plataformas SDR são apresentados e comparados. Os resultados obtidos demonstram a capacidade do software desenvolvido ser usado como parte de um sistema de Radar Contínuo Modulado na Frequência baseado em plataformas de Rádio Definido por Software de baixo custo, e também o potencial deste sistema ser usado para a detecção de alvos, desde que seja resolvido o problema do atraso adicional criado pelas plataformas SDR usadas

Sistema de radar SDR de onda continua múltiple implementado mediante GNU Radio

Software Defined Radio (SDR) is a technology with recognition in Telecommunication industry because of its capacity of developing reconfigurable communication systems. This paper presents the implementation and field-testing evaluation for a low-cost radar system using the gr-radar toolbox created into the version 3.7.4 of GNU Radio. Tests allowed to measure distances and velocities of one target in movement. Velocity estimation errors were obtained with 1.8 % and 3.22 % in a round trip. Range estimation errors were also obtained with 1.56 % and 2.75 % in a round trip. Radar system was configured to transmit at 2.4 GHz with Multiple CW technique. The test scenario was the Nueva Granada Military University Campus in Colombia. The results are oriented toward use this tools for deepening on basic Radar principles with low-cost devices.Radio definido por software (SDR) es una tecnología reconocida en la industria de telecomunicaciones por su capacidad para desarrollar sistemas de comunicación reconfigurables. Este trabajo presenta el diseño, la implementación y la evaluación de un radar de bajo costo utilizando la librería gr-radar disponible desde la versión 3.7.4 de GNU Radio. La evaluación de desempeño del radar implementado se realizó mediante pruebas en espacio abierto donde fue posible medir con gran exactitud la distancia y la velocidad de un objeto en movimiento. En la estimación de la velocidad se obtuvo un error de 1,98 % en el trayecto de ida y de 3,22 % en el de regreso. Para la estimación de posición se obtuvo un error promedio de 1,56 % para los trayectos de ida y de 2,75 % en el regreso. El sistema de radar fue configurado para transmitir a 2,4 GHz con la técnica de ondas continuas múltiples. El escenario en el que se desarrolló la prueba del sistema fue el campus de la Universidad Militar Nueva Granada, en Cajicá (Colombia). Los resultados mostrados en este trabajo se orientan a la profundización en las técnicas de radar empleando herramientas de bajo costo

UAV for Landmine Detection Using SDR-Based GPR Technology

This chapter presents an approach for explosive-landmine detection on-board an autonomous aerial drone. The chapter describes the design, implementation and integration of a ground penetrating radar (GPR) using a software defined radio (SDR) platform into the aerial drone. The chapter?s goal is first to tackle in detail the development of a custom-designed lightweight GPR by approaching interplay between hardware and software radio on an SDR platform. The SDR-based GPR system results on a much lighter sensing device compared against the conventional GPR systems found in the literature and with the capability of re-configuration in real-time for different landmines and terrains, with the capability of detecting landmines under terrains with different dielectric characteristics. Secondly, the chapter introduce the integration of the SDR-based GPR into an autonomous drone by describing the mechanical integration, communication system, the graphical user interface (GUI) together with the landmine detection and geo-mapping. This chapter approach completely the hardware and software implementation topics of the on-board GPR system given first a comprehensive background of the software-defined radar technology and second presenting the main features of the Tx and Rx modules. Additional details are presented related with the mechanical and functional integration of the GPR into the UAV system

DESIGN AND IMPLEMENTATION OF SOFTWARE-DEFINED DOPPLER RADAR

The subject of this article is a study of the possibility of practical implementation of a Doppler CW radar based on software-defined radio (SDR) technology. The paper presents overview of two technologies. Initially the architecture and basic characteristics of a Doppler CW radar are described, followed by an overview of SDR concept and types and characteristics of typical constructive elements for its realization.  Finally, a practical implementation by usage of USRP front-end and the GNU Radio Framework is presented. For the successful implementation of the Doppler CW radar architecture an additional amplifier is included. The material presents the results of tests performed using the practical implementation of a Doppler CW SDR radar, demonstrating the functionality of the implementation

A Software Radio Based Ionosonde Using GNU Radio

ABSTRACT The Canadian Advanced Digital Ionosonde (CADI) is used to study and investigate the structure and motion o f the ionosphere. The main components of CADI are implemented in microcontroller based digital logic. Due to the increased speed and reconfiguration capability of modem FPGAs (Field Programmable Gate Arrays) and ADCs (Analog-Digital Converters), this project is aimed to develop an ionosonde based on an open source radio software platform, GNU Radio, in conjunction with its hardware support, the Universal Software Radio Peripheral (USRP). The lowest cost FPGA, Cyclone EP1C12Q240C8 is selected to control Analog Digital Converter to transmit a HF (High Frequency) signal and to decimate and down convert the signal at the receiver side, which is controlled by a USB controller, and to load the FPGA configuration image through GNU radio platform. To obtain a good range resolution and low noise level, the signal is modulated by a 113-bit Legendre sequence with a preamble packed at front for synchronization. Based on the experimental results, the discussion and conclusion are included

Exploiting the Automatic Dependent Surveillance-Broadcast System via False Target Injection

A new aircraft surveillance system, Automatic Dependent Surveillance-Broadcast (ADS-B), is being introduced by the Federal Aviation Administration (FAA) with mandated implementation in the United States by the year 2020. The rapid deployment of the system with current test-beds spread across the U.S. leaves very little chance for anyone to test the abilities of the system and more importantly the flaws of the system. The research conducted within this thesis explores some of the weaknesses of the system to include the relative ease with which false aircraft targets can be injected. As part of a proof of concept, false ADS-B messages were successfully generated using a system comprised of GNU Radio, a Universal Software Radio Peripheral (USRP), and software developed by the author. The ability to generate, transmit, and insert spoofed ADS-B messages on the display of a commercial ADS-B receiver, identified and exploited a weakness of the ADS-B system. Four demonstrations, conducted within an experimental environment, displayed the potential uses of the system created through this research and its associated impacts