Communications techniques and equipment: A compilation

This Compilation is devoted to equipment and techniques in the field of communications. It contains three sections. One section is on telemetry, including articles on radar and antennas. The second section describes techniques and equipment for coding and handling data. The third and final section includes descriptions of amplifiers, receivers, and other communications subsystems

Interactive Real-Time Embedded Systems Education Infused with Applied Internet Telephony

The transition from traditional circuit-switched phone systems to modern packet-based Internet telephony networks demands tools to support Voice over Internet Protocol (VoIP) development. In this paper, we introduce the XinuPhone, an integrated hardware/software approach for educating users about VoIP technology on a real-time embedded platform. We propose modular course topics for design-oriented, hands-on laboratory exercises: filter design, timing, serial communications, interrupts and resource budgeting, network transmission, and system benchmarking. Our open-source software platform encourages development and testing of new CODECs alongside existing standards, unlike similar commercial solutions. Furthermore, the supporting hardware features inexpensive, readily available components designed specifically for educational and research users on a limited budget. The XinuPhone is especially good for experimenting with design trade-offs as well as interactions between real-time software and hardware components

A development and implementation of a tinnitus treatment method

Tinnitus is a physiological phenomenon where a person listens sounds which have not been generated by any external source. Today, many people suffer this condition. Although, in very few cases therapeutic methods completely eliminate tinnitus, it is possible to apply a variety of techniques to improve the quality of life of people with this condition. One of the most used methods to treat tinnitus consists of masking the tinnitus using an external sound. The main goal of this work is to present the development of a tinnitus treatment method, which optimizes the synthesized sounds in order to improve the life's quality of the user. Subjective tests and experimental results are used to analyze the performance of the method.Fil: Uriz, Alejandro José. Universidad Nacional de Mar del Plata. Facultad de Ingeniería. Departamento de Electrónica. Laboratorio de Comunicaciones; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Agüero, Pablo Daniel. Universidad Nacional de Mar del Plata. Facultad de Ingeniería. Departamento de Electrónica. Laboratorio de Comunicaciones; ArgentinaFil: Tulli, Juan Carlos. Universidad Nacional de Mar del Plata. Facultad de Ingeniería. Departamento de Electrónica. Laboratorio de Comunicaciones; ArgentinaFil: Castiñeira Moreira, Jorge. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Mar del Plata. Facultad de Ingeniería. Departamento de Electrónica. Laboratorio de Comunicaciones; ArgentinaFil: González, Esteban Lucio. Universidad Nacional de Mar del Plata. Facultad de Ingeniería. Departamento de Electrónica. Laboratorio de Comunicaciones; ArgentinaFil: Moscardi, Graciela. Universidad FASTA "Santo Tomas de Aquino"; ArgentinaFil: Sajama, Elber Emanuel. Universidad Nacional de Mar del Plata. Facultad de Ingeniería. Departamento de Electrónica. Laboratorio de Comunicaciones; Argentin

New Synchronization Method for Transmission Systems with Variable Length of Bits

Based on the Spartan 3E evaluation module, a flexible platform for the implementation of different algorithms for A/D conversion was developed. The aim of presented work was to improve the concept of the sampling rate adaptation to the input signal rate of change in terms of practical issues including synchronization of delta codecs. The new, original synchronization method, useful in systems dedicated for transmission of variable duration of bits was proposed and experimentally verified. Performed measures and observations have shown elimination of the synchronization lose phenomeno

Narrative music: towards an understanding of musical narrative functions in multimedia

As the computer screen is replacing the book as the dominant medium for communication (Kress, 2003), questions about how meaning is constituted by the multimodal interaction of different media (including music) is becoming increasingly important in contemporary research of pedagogy, sociology and media studies. The overall aim with this licentiate thesis is to explore musical narrative functions as they appear in multimedia such as film and computer games. The thesis is based on three publications. Publication 1 proposes a classification of musical narrative functions, with 6 narrative classes(the Emotive, Informative, Descriptive, Guiding, Temporal and Rhetorical classes) and 11 categories. The relational interplay of music with contextual factors is emphasized. Publication 2 describes the design of a software tool, REMUPP (Relations Between Musical Parameters and Perceived Properties), to be used for experimental studies of musical expression. REMUPP is used for real time alteration of musical expression, by the manipulation of musical parameters such as tempo, harmony, rhythm, articulation, etc. Publication 3 describes a quasi-experiment using REMUPP, where a group of young participants (12-13 years old) were given the task of adapting musical expression – by manipulating 7 parameters – to make it fit 3 visual scenes shown on a computer screen. They also answered a questionnaire asking about their musical backgrounds and habits of listening to music, watching movies and playing computer games. Numerical data from the manipulations were analyzed statistically with regards to the preferred values of the musical parameters in relation to the different visual scenes. The results indicated awareness and knowledge about codes and conventions of musical narrative functions, and were to some degree affected by the participants’ gender, musical backgrounds and media habits

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

Applications of satellite technology for regional organizations (Project ASTRO)

The direct arithmetic processing of adaptive delta modulation (ADM) encoded signals, conversion from ADM encoded signals to pulse code modulation (PCM) encoded signals, and conversion from PCM to ADM encoded signals are discussed. It is shown that signals which are ADM encoded can be arithmetically processed directly, without first decoding. Operating on the DM bit stream, and employing only standard digital hardware, the sum, difference and product can be obtained in PCM and ADM format

Preliminary candidate advanced avionics system for general aviation

An integrated avionics system design was carried out to the level which indicates subsystem function, and the methods of overall system integration. Sufficient detail was included to allow identification of possible system component technologies, and to perform reliability, modularity, maintainability, cost, and risk analysis upon the system design. Retrofit to older aircraft, availability of this system to the single engine two place aircraft, was considered

NASA Tech Briefs Index, 1977, volume 2, numbers 1-4

Announcements of new technology derived from the research and development activities of NASA are presented. Abstracts, and indexes for subject, personal author, originating center, and Tech Brief number are presented for 1977