Software-Defined Radio Demonstrators: An Example and Future Trends

Software-defined radio requires the combination of software-based signal processing and the enabling hardware components. In this paper, we present an overview of the criteria for such platforms and the current state of development and future trends in this area. This paper will also provide details of a high-performance flexible radio platform called the maynooth adaptable radio system (MARS) that was developed to explore the use of software-defined radio concepts in the provision of infrastructure elements in a telecommunications application, such as mobile phone basestations or multimedia broadcasters

Experimental results of non-radiative calibration of a tower top adaptive array

The need for calibration in antenna arrays is a persistent challenge and is one of the impediments to their widespread integration into communication infrastructures. The choice of antenna array structure dictates the means by which calibration can be achieved. The antenna structure used here is a distributed source array with an interconnected measurement structure for calibration. This non-radiative approach was taken to remove the need for external calibration sources, or computationally expensive modelling. This approach requires a calibration algorithm to utilise the measurement structure to get the best results. This paper will present a set of three such calibration algorithms used on an experimental setup to show the effectiveness of such calibration

Reconfigurable Radio Hardware & Software Integration and Testing

Software Defined Radio efforts are focused in both software and hardware areas. Nowadays software products are designed to allow newer and better software radio products for a quick reconfiguration and adaptation to new challenges. With the proliferation of reconfigurable radio software, having a complete SDR system has never been as approachable/accessible. This paper focused on the integration and testing efforts of a RF front-end with the existing reconfigurable radio software called IRIS [1] (Implementing Radio in Software) developed by CTVR (Centre for Telecommunications Value-Chain Research). Several papers were presented at SDR’07 Forum in Denver (CO) [2][3] regarding this RF front-end and its lowlevel software elements. The RF front-end consists of four hardware elements, namely a radio transmitter, a radio receiver, a baseband interface and a PC to perform signal processing and configuration. Additionally, there is a substantial software element to configure the hardware and to receive/transmit data via a USB 2.0 interface. The IRIS system is a component framework for building radio systems, which integrates a great variety of signal processing components. In order to integrate our RF front-end with IRIS two new IRIS components were written in C++: one for transmitting and another for receiving. This integration was possible thanks to the high quality of both software elements: IRIS and the RF front-end software elements (USB driver, embedded code and additional API libraries). High quality measured in terms of reusable, maintainable, modifiable and extendible. The full paper version will include a demonstration of the complete SDR system: IRIS and RF front-end working together. This demonstration consists of building two radios in IRIS, one for transmission and another for reception of an image file using DBPSK modulation. This radio makes use of the two new IRIS components that communicate with our RF front-end. Integrations with other software systems for building radios are planned for the near future, such as OSSIE system by Virginia Tech. All this work will lead us to a better understanding about these systems, which will help us to face the challenge of building an improved one

Software Defined Radio Transceiver Implementation

This document presents the design and implementation of a low cost reconfigurable radio transceiver platform. The platform will be used as a research tool in the investigation of software defined radio techniques. The hardware presented is an evolution of work presented at the 2006 RIA colloquium. The platform consists of four hardware elements, namely a radio transmitter, a radio receiver, a baseband interface and a PC to perform signal processing and configuration. Data and control communication is performed via a USB 2.0 interface between the transceiver and a laptop PC. The platform development included a substantial software element to configure the hardware and to receive and transmit data between the PC and the transceiver. The technical choices, design and realization of the prototype are discussed

“Lessons learnt in developing a SDR Platform with USB interface”

Building a new Software Defined Radio (SDR) system requires multidisciplinary research covering the engineering disciplines of communication systems, radio frequency, digital and analog hardware, software and digital signal processing. This paper focuses on the efforts at the low-level software development, such as device drivers, embedded source code at firmware-space and Application- Programming Interfaces (APIs) at user-space. In the early stages of constructing a SDR platform, design decisions are made regarding the interface between the SDR hardware and the PC. These decisions are of great importance and will determine the complexity of the low-level software development, its interoperability with third-party tools for waveform development and its efficiency in terms of bandwidth and configurability. This position paper reviews the experiences in using a USB interface between the PC and the SDR platform and the corresponding impact in the software development stage

Hardware implementation of a versatile low-cost mixed-signal platform for SDR experimentation

This paper presents the design of a reconfigurable mixedsignal platform used in the Software Defined Radio context.It is a single board part of a pre-existing modular system operating from 1.6 to 2.5 GHz that supports GSM1800,DCS1800, PCS1900, UMTS-FDD, UMTS-TDD and 802.11b standards. Its purpose is to facilitate configuration and data exchange between a computer and an RF transceiver. Technical choices, design and overall performances of the prototype are discussed

Reconfigurable High Frequency Class S Power Amplifier Demonstrator

This paper presents an end-to-end high frequency class S power amplifier. A description of the full testbench and some important points on generation of RF outputs from FPGA devices and current mode class D design are given. Experimental measurements are provided for the prototype PA consisting of a signal generator, analog to digital converter, driver circuit, current mode class D switching stage and bandpass filter. Theory and experimentally measured results for this prototype are presented for a multi tone signal centred at 930 MHz and with a total output power of 24.7dBm

Experiences in the co-design of software and hardware elements in a SDR platform

The Center for Telecommunications Value-Chain Research (CTVR) has developed an integrated software radio platform that combines a reconfigurable hardware radio platform, called NUIM SDR transceiver, and a modular software radio framework, called Implementing Radio in Software (IRIS). This paper outlines the design challenges in achieving the integration between these two systems, and also presents experimental results. The test consists of transmitting an image file using DQPSK modulation with IRIS and the Universal Software Radio Peripheral (USRP) RF front-end at 2.41GHz, and receiving it with IRIS and the NUIM SDR transceiver. The integrated software radio platform presented in this paper enables new research opportunities testing real-world environments and developing cognitive radios for dynamic spectrum access techniques

Taking an evaluative stance to decision-making about professional development options in early childhood education and care

This article builds on our ongoing work in conceptualising an ‘evaluative stance’ framework to assist in understanding how leaders in the field of early childhood education and care (ECEC) make decisions about the selection of professional development options for themselves and their staff. It introduces the notion that evaluative mindsets can be considered in terms of attitudes towards decision-making that are based on personal epistemologies. Drawing on data from semi-structured interviews, it explores the mindsets of six experienced leaders in two long-established ECEC organisations in Australia with respect to their decision-making about professional development. The article concludes with a consideration of the potential utility of the framework and the coding template used in this exploratory study

The role of the scientist-practitioner model in the teaching of psychology: preliminary results from the AUTC funded project Learning Outcomes and Curriculum Development in Psychology

The Australian Universities Teaching Committee (AUTC) is committed to the identification of ‘examples of best practice in teaching and learning in Australian universities at the level of discipline or field of study’. The AUTC funded project Learning Outcomes and Curriculum Development in Psychology was awarded this year to a team representing a diverse cross-section of Schools and Departments of Psychology in Australia. The project brief demands ‘an evaluative overview of courses… with a focus on the specification and assessment of learning outcomes and must identify strategic directions for universities to enhance teaching and learning in these areas’. Although the final project outcomes will include a discussion of the teaching of psychology beyond that taking place within Schools and Departments of Psychology, this preliminary report will consider only information relevant to the teaching of psychology in core programs within Australian Psychological Society (APS) accredited academic organisational units (AOUs)