Digital Modulations Using the Universal Software Radio Peripheral

Software defined radios (SDRs) are versatile systems that integrate hardware and software to create a reprogrammable wireless system. Due to the versatility and hardware requirements of a SDR, they are typically expensive and not always affordable for educational institutions. GNU Radio is a free software package that allows users to do signal processing on any computer using python and C++. Using the Universal Software Radio Peripheral (USRP) board in conjunction with a standard personal computer (PC), a RF daughterboard, and the GNU Radio software, we can create a software defined radio that can transmit, receive, and process signals. Because the USRP a personal computer to perform symbol generation, less specialized hardware is needed for the implementation of a software radio, thus reducing the overall system cost. The low cost of a USRP-based SDR enables the implementation of SDRs in laboratory courses, allowing students to learn about digital signal processing along with wireless communication systems. The objective of this senior project is to develop a low-cost SDR that can be used to support student learning of digital wireless communications in a laboratory setting. To demonstrate the capabilities of the SDR, example modulations using BFSK and BASK were developed. In addition, supporting documents like a “quick-start guide” were created to assist in the implementation of SDRs in a digital communications lab. The RFX400 daughterboard was used as a front end with the USRP to test if a college level student could use this hardware with GNU Radio to transmit a modulated signal. The carrier frequencies of these modulated signals were increased to within the bandwidth of the RFX400, 400 to 500 MHz, then these signals were transmitted and successfully received but not with the same clarity as the signal before transmission. Transmitting signals through the air always causes signal degradation, but the number of samples that the USRP uses during reception also affects the quality of the received signal. The USRP and GNU Radio are the ideal hardware and software combination to use by students due to the affordability, versatility, and ease of use

Mechanical systems readiness assessment and performance monitoring study

The problem of mechanical devices which lack the real-time readiness assessment and performance monitoring capability required for future space missions is studied. The results of a test program to establish the feasibility of implementing structure borne acoustics, a nondestructive test technique, are described. The program included the monitoring of operational acoustic signatures of five separate mechanical components, each possessing distinct sound characteristics. Acoustic signatures were established for normal operation of each component. Critical failure modes were then inserted into the test components, and faulted acoustic signatures obtained. Predominant features of the sound signature were related back to operational events occurring within the components both for normal and failure mode operations. All of these steps can be automated. The structure borne acoustics technique lends itself to reducing checkout time, simplifying maintenance procedures, and reducing manual involvement in the checkout, operation, maintenance, and fault diagnosis of mechanical systems

The use of home experimentation kits for distance students in first-year undergraduate electronics

Laboratory and practical classes are an important part of the education of students in electronics and electrical engineering. &quot;Hands-on&quot; experience is critical for any engineer working in these fields in particular. For many years, delivering engineering practicals to distance-education students has been a tremendous challenge for universities. For a number of years now, students enrolled in the common first-year electronics course by distance mode at Deakin University have received a home experimentation kit. Using the kit and a laboratory manual, students are required to complete a number of experiments based on components included in the kit. The kit supports a full range of practical activities for digital electronics, and a more limited range of activities for analog electronics. With the kit, off campus students are supplied software for simulating AC electronic circuits, such as amplifiers and rectifiers. In this report we examine the past use of this kit and software,review anecdotal student experiences with the package, and propose changes to it and to other curriculum resources, aiming to enhance the use of the kit by distance students. Key curriculum resources planned are a web-based \u27companion\u27 for the components in and the use of the kit, and two additions to the kit itself: a battery powered function generator, and a PC-based oscilloscope.<br /

A software-based ultrasound system for medical diagnosis

Thesis (M. Eng.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 1997.Includes bibliographical references (p. 113-115).by Samir Ram Thadani.M.Eng