Hardware prototyping and validation of a W-ΔDOR digital signal processor

Microwave tracking, usually performed by on ground processing of the signals coming from a spacecraft, represents a crucial aspect in every deep-space mission. Various noise sources, including receiver noise, affect these signals, limiting the accuracy of the radiometric measurements obtained from the radio link. There are several methods used for spacecraft tracking, including the Delta-Differential One-Way Ranging (ΔDOR) technique. In the past years, European Space Agency (ESA) missions relied on a narrowband ΔDOR system for navigation in the cruise phase. To limit the adverse effect of nonlinearities in the receiving chain, an innovative wideband approach to ΔDOR measurements has recently been proposed. This work presents the hardware implementation of a new version of the ESA X/Ka Deep Space Transponder based on the new tracking technique named Wideband ΔDOR (W-ΔDOR). The architecture of the new transponder guarantees backward compatibility with narrowband ΔDOR

AREA AND POWER-EFFICIENT RECONFIGURABLE DIGITAL DOWN CONVERTER ON FPGA

This paper presents a field-programmable gate array (FPGA)-based digital down converter (DDC) that can reduce the bandwidth from about 70 MHz to 182.292 kHz. The proposed DDC consists of a polyphase COordinate Rotation DIgital Computer (CORDIC) processor and a multirate filter. The advantage of polyphase CORDIC processor is to process with high sample rate input data and produces computational efficient noiseless baseband spectrum. The pipeline multirate filter works at a high clock speed. Moreover, the multirate filter generates a fractional sample rate factor using a cubic B-spline Farrow filter. The proposed DDC is coded with optimal hardware description language (HDL) and tested on Kintex-7 Xilinx FPGA as the target device. Experimental results indicate that the proposed design saves chip area, power consumption and operates at high speed without loss of any functionality. Additionally, the proposed design offers sufficient spurious-free dynamic range (SFDR) and produces less than 1 Hz frequency resolution at the output

A combined receiver front-end for Bluetooth and HiperLAN/2

A Software Defined Radio is a radio receiver that is reconfigurable by software. This reconfigurability leads to flexibility that can be used to offer more functionality to the user. Also, because common reconfigurable hardware can be used for very diverse radio interfaces, production and logistics can be faster and cheaper. In our Software Defined Radio project we aim at a receiver that is able to receive signals of any contemporary or future radio standard. However, because we need tangible specifications in order to design, we have chosen to implement a combination of two rather different standards: Bluetooth and HiperLAN/2. Both the analogue and the digital/software parts are included in the design. A CMOS integrated wideband analogue front-end containing a low noise amplifier, downconversion mixers and filters has been designed. This front-end\ud is connected to a PCB that contains two analogue-to-digital convertors and a sample rate convertor (SRC). The output of this board is connected to a standard PC through a digital I/O board with PCI bus. Software on this PC performs the demodulation.\ud We conclude that an analog wide-band front-end with a flexible SRC combined with appropriate software on an inherently flexible PC forms a promising architecture for Software Defined Radio

Banco de testes para monitoramento sub-Nyquist de espectro de banda larga

Radioelectric spectrum management is a concern for today’s world, mainly due to the misuse that has been given to this resource through the years, especially on the UHF band. To address this problem, a testbed for sub-Nyquist Wideband Spectrum Monitoring was built, that includes a web interface to remotely measure occupancy of the UHF band. To achieve the above, an RF interface that allows tuning UHF frequencies with an instantaneous bandwidth of 95 MHz was built. Afterwards, a Random Demodulator was connected, and then an embedded system performed sub--Nyquist sampling and spectrum recovery. The embedded system connected to an information system that serves a web page, through which remote users can perform UHF band monitoring. Experimental results showed that spectrum sensing can be achieved by using different algorithms on certain sparse spectra. In addition, the aforementioned web interface allowed simultaneous user connections, in order to perform independent measurements by sharing a hardware subsystem.La gestión del espectro radioeléctrico es una preocupación en la actualidad, hecho derivado, ante todo, del mal uso que se ha dado a este recurso a través de los años, especialmente en la banda de UHF. Para afrontar este problema, se construyó un banco de pruebas para la supervisión del espectro de banda ancha a través de muestreo sub-Nyquist, el cual incluye una interfaz web para medir de forma remota la ocupación de la banda UHF. Para lograr esto, se construyó una interfaz RF que permitiría sintonizar frecuencias UHF con un ancho de banda instantáneo de 95 MHz. Después, se conectó un demodulador aleatorio; y luego, un sistema embebido realizaría el muestreo sub-Nyquist y la recuperación del espectro. Este se conectaría, a su turno, con un sistema de información que sirve una página web, a través de la cual los usuarios remotos pueden realizar la supervisión de la banda de UHF. Los resultados muestran que la detección del espectro se puede lograr mediante diferentes algoritmos en ciertos espectros dispersos. Además, la interfaz web permitió que existiesen conexiones de usuario simultáneas, de tal manera que se realizaran mediciones independientes compartiendo el subsistema de hardware.O gerenciamento do espectro radioelétrico é uma preocupação na atualidade, fato derivado, inicialmente, do mau uso que se tem dado a esse recurso através dos anos, especialmente na banda de UHF. Para enfrentar esse problema, construiu-se um banco de testes para a supervisão do espectro de banda larga por meio de amostragem sub-Nyquist, a qual inclui uma interface web para medir de forma remota a ocupação da banda UHF. Para isso, construiu-se uma interface RF que permitiria sintonizar frequências UHF com uma largura de banda instantânea de 95 MHz. Em seguida, ligou-se um demodulador aleatório; logo, um sistema embebido realizaria a amostragem sub-Nyquist e a recuperação do espectro. Este se ligaria, por sua vez, com um sistema de informação que serve um site, através do qual os usuários remotos podem realizar a supervisão da banda de UHF. Os resultados mostram que a detecção do espectro pode ser conseguida mediante diferentes algoritmos em certos espectros dispersos. Além disso, a interface web permitiu que existissem conexões de usuário simultâneas, de tal maneira que se realizassem medidas independentes compartilhando o subsistema de hardware.&nbsp

RHINO software-defined radio processing blocks

This MSc project focuses on the design and implementation of a library of parameterizable, modular and reusable Digital IP blocks designed around use in Software-Defined Radio (SDR) applications and compatibility with the RHINO platform. The RHINO platform has commonalities with the better known ROACH platform, but it is a significantly cut-down and lowercost alternative which has similarities in the interfacing and FPGA/Processor interconnects of ROACH. The purpose of the library and design framework presented in this work aims to alleviate some of the commercial, high cost and static structure concerns about IP cores provided by FPGA manufactures and third-party IP vendors. It will also work around the lack of parameters and bus compatibility issues often encountered when using the freely available open resources. The RHINO hardware platform will be used for running practical applications and testing of the blocks. The HDL library that is being constructed is targeted towards both novice and experienced low-level HDL developers who can download and use it for free, and it will provide them experience of using IP Cores that support open bus interfaces in order to exploit SoC design without commercial, parameter and bus compatibility limitations. The provided modules will be of particularly benefit to the novice developers in providing ready-made examples of processing blocks, as well as parameterization settings for the interfacing blocks and associated RF receiver side configuration settings; all together these examples will help new developers establish effective ways to build their own SDR prototypes using RHINO

UWB Pulse Radar for Human Imaging and Doppler Detection Applications

We were motivated to develop new technologies capable of identifying human life through walls. Our goal is to pinpoint multiple people at a time, which could pay dividends during military operations, disaster rescue efforts, or assisted-living. Such system requires the combination of two features in one platform: seeing-through wall localization and vital signs Doppler detection. Ultra-wideband (UWB) radar technology has been used due to its distinct advantages, such as ultra-low power, fine imaging resolution, good penetrating through wall characteristics, and high performance in noisy environment. Not only being widely used in imaging systems and ground penetrating detection, UWB radar also targets Doppler sensing, precise positioning and tracking, communications and measurement, and etc. A robust UWB pulse radar prototype has been developed and is presented here. The UWB pulse radar prototype integrates seeing-through imaging and Doppler detection features in one platform. Many challenges existing in implementing such a radar have been addressed extensively in this dissertation. Two Vivaldi antenna arrays have been designed and fabricated to cover 1.5-4.5 GHz and 1.5-10 GHz, respectively. A carrier-based pulse radar transceiver has been implemented to achieve a high dynamic range of 65dB. A 100 GSPS data acquisition module is prototyped using the off-the-shelf field-programmable gate array (FPGA) and analog-to-digital converter (ADC) based on a low cost solution: equivalent time sampling scheme. Ptolemy and transient simulation tools are used to accurately emulate the linear and nonlinear components in the comprehensive simulation platform, incorporated with electromagnetic theory to account for through wall effect and radar scattering. Imaging and Doppler detection examples have been given to demonstrate that such a “Biometrics-at-a-glance” would have a great impact on the security, rescuing, and biomedical applications in the future

Studies in Software-Defined Radio System Implementation

Over the past decade, software-defined radios (SDRs) have an increasingly prevalent aspect of wireless communication systems. Different than traditional hardware radios which implement radio protocols using static electrical circuit, SDRs implement significant aspects of physical radio protocol using software programs running on a host processor. Because they use software to implement most of the radio functionality, SDRs are much more easily modified, edited, and upgraded than their hardware-defined counterparts. Consequently, researchers and developers have been developing previously hardware-defined radio systems within software. Thus, communication standards can be tested under different conditions or swapped out entirely by simply changing some code. Additionally, developers hope to implement more advanced functionality with SDRs such as cognitive radios that can sense the conditions of the environment and change parameters or protocol accordingly. This paper will outline the major aspects of SDRs including their explanation, advantages, and architecture. As SDRs have become more commonplace, many companies and organizations have developed hardware front-ends and software packages to help develop software radios. The most prominent hardware front-ends to date have been the USRP hardware boards. Additionally, many software packages exist for SDR development, including the open source GNU Radio and OSSIE and the closed source Simulink and Labview SDR packages. Using these development tools, researchers have developed many of the most relevant radio standards. This paper will explain the major hardware and software development tools for creating SDRs, and it will explain some of the most important SDR projects that have been implemented to date