Software-defined radio using LabVIEW and the PC sound card: A teaching platform for digital communications

Different modulation techniques and protocols require a standard communications laboratory for engineering courses to be equipped with a broad set of equipment, tools and accessories. However, the high costs involved in a hardware-based laboratory can become prohibitively expensive for many institutions. Software simulations alone can replicate most real-world applications with much lower costs. Nevertheless, they do not replace the real-world feeling provided by hardware-based systems, which can produce and receive physical signals to and from the exterior media. Advances in computer technology are allowing software-defined radio (SDR) concepts to be applied in many areas of communications. In this type of system, the baseband processing is performed completely in software while an analog RF front end hardware can be used for RF processing. The use of a software-defined radio platform in a digital communications laboratory can offer the benefits of software simulations coupled with the enthusiasm presented by hardware-based systems. A low-cost software-defined radio teaching platform implemented in LabVIEW using the personal computer sound card was developed for a digital communications laboratory along with a set of exercises to help students assimilate the concepts involved in communications theory and system implementation. This system allows for the generation, reception, processing, and analysis of signals in a 4 QAM (quadrature amplitude modulation) transceiver using the personal computer sound card to transmit and receive modulated signals. This teaching platform provides the means necessary to explore the theoretical concepts of digital communication systems in a laboratory environment. National Instruments\u27 LabVIEW graphical programming environment allows a more intuitive way of coding, which helps students to spend more time learning the relevant theory concepts and less time coding the applications. Being a flexible and modular system, modifications can be made for optimization and use with different and/or more complex techniques

Developing Engineering Learning Objects Online Portal with LabVIEW and an Open Source Web Content Management System

Learning objects (LOs) are independent chunks of knowledge normally used for instructional or learning purposes. LOs are normally reusable in the sense that they can be adopted and adapted for various learning and instructional scenarios. They are also tagged with metadata which includes descriptive information allowing them to be used and searched easily. LOs are sometimes metaphored as being a LEGO. Examples of LOs could contain multimedia content, instructional content, learning objectives, instructional software and software tools, and computer simulations. Many LOs are designed to be mediated online. In engineering education, computer simulations based learning objects could be the most beneficial for conveying hard engineering concepts for the engineering science learner. Computer simulations have been reported to facilitate conceptual understanding and leaving positive impact on students learning in numerous number of engineering education research articles. In the last two decades, many software packages have been developed for enhancing the engineering design and analysis process, examples are Matlab/Simulink, PSpice, LabVIEW, etc. These has been used consequently by academics for enhancing their students learning. LabVIEW is one of the most versatile computer software packages. It is used comprehensively in the industry as well as in academia. LabVIEW started as computer software interface of PC based data question equipments, however, it has grown much beyond that offering comprehensive toolkits and already implemented functions. Also it has great connectivity facilities with Matlab/Simulink, C++, and Visual Basic allowing communicating already developed codes in the latter with its core engine. The other important specification of LabVIEW is its embedded internet tools enabling publishing its programmed GUIs on the world wide web in easy and handy way. Web content management systems is the third generation of web publishing applications after HTML and web authoring software packages such as FrontPage and Dreamweaver. It is used to manage and control a large, dynamic collection of Web material (HTML documents and their associated images). A WCMS facilitates content creation, content control, editing, and many essential Web maintenance functions. In contrast with the web development tools such as HTML, FrontPage, Dreamweaver, etc., a CMS enables faster development, cost effectiveness, and online flexibility. The basic idea of any web content management system is that a non-technical person often needs to be able to keep their own website up-to-date without having to call on a web developer to make changes every time. Of course there are some things that can only be done by a web developer, but for simpler tasks such as changing the wording of a paragraph, it is an unnecessary burden and expense for both parties if you have to get a developer to make the changes. This paper provides an A to Z prescription of implementing a standardized Learning Objects online portal. This describing in detail a LabVIEW based Learning Object architecture, using a proper IEEE LOM metadata generation tool, and finally how on the top of that a Joomla web content management system can be used for developing the online portal

Software defined radio (SDR) on radiocommunications teaching

The recent outbreak of Software Defined Radios (SDR), where traditionally hardware components are substituted by software, have revolutionized the way we understand and manage radiocommunications. The current state of technology allows low cost SDR receivers to tune emissions in a simple way with almost no experience and little effort. The great flexibility of this equipment allows a perfect adaptation of the practice part of the subject to the theory objectives and makes possible to learn outside the classroom, something unthinkable until now. To achieve this, the student only needs a low-cost SDR receiver, a computer and some free software. This paper presents a new teaching methodology for practicing radiocommunications subject using a workstation based on a SDR device that can receive, display and analyze radio transmissions. Subject learning outcomes and skills are acquired and strengthened through experimentation with this new kind of devices. This platform also represents a significant saving because avoids our university to buy expensive and closed "training kits".CUD Universidad de Vigo Grupo de Investigación Señales, Sistemas y Comunicaciones Navales. Universidad de Cádi

Teaching Hardware Design of Fixed-Point Digital Signal Processing Systems

Signal processing theory and practice are enabling and driving forces behind multimedia devices, communications systems, and even such diverse fields as automotive and medical systems. Over 90 % of the signal processing systems on the market used fixed-point arithmetic because of the cost, power, and area savings that fixed-point systems provide. However, most colleges and universities do not teach or teach only a very little fixed-point signal processing. This issue is being addressed slowly around the country but now a new challenge or opportunity presents itself. As reconfigurable logic technology matures, field-programmable gate arrays (FPGAs) are increasingly used for signal processing systems. They have the advantage of tremendous throughput, great flexibility, and system integration. The challenge is that signal processing in FPGAs is a much less constrained problem than signal processing in special purpose microprocessors. The opportunity arises in that it is now possible to explore more options and, more especially, to take a more systems-level approach to signal processing systems. In short, designing a signal processing system using FPGAs provides opportunities to look at many system design issues and trade-offs in a classroom setting. We have developed a course to teach signal processing in FPGAs at Georgia Institute of Technology and in this paper we consider the challenges and methods of teaching fixedpoint system design in this course. We discuss the topics chosen and how they differ from traditional microprocessor-based courses. We also discuss how systems engineering concepts are woven into the course.

Intelligent composite layup by the application of low cost tracking and projection technologies

Hand layup is still the dominant forming process for the creation of the widest range of complex geometry and mixed material composite parts. However, this process is still poorly understood and informed, limiting productivity. This paper seeks to address this issue by proposing a novel and low cost system enabling a laminator to be guided in real-time, based on a predetermined instruction set, thus improving the standardisation of produced components. Within this paper the current methodologies are critiqued and future trends are predicted, prior to introducing the required input and outputs, and developing the implemented system. As a demonstrator a U-Shaped component typical of the complex geometry found in many difficult to manufacture composite parts was chosen, and its drapeability assessed by the use of a kinematic drape simulation tool. An experienced laminator's knowledgebase was then used to divide the tool into a finite number of features, with layup conducted by projecting and sequentially highlighting target features while tracking a laminator's hand movements across the ply. The system has been implemented with affordable hardware and demonstrates tangible benefits in comparison to currently employed laser-based systems. It has shown remarkable success to date, with rapid Technology Readiness Level advancement. This is a major stepping stone towards augmenting manual labour, with further benefits including more appropriate automation