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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
41

HIGH SHOCK, COMPUTERIZED, MINIATURE, AIRBORNE PCM/FM TELEMETRY SYSTEM

Svensson, Ake, Maoz, Michael 11 1900 (has links)
International Telemetering Conference Proceedings / October 30-November 02, 1989 / Town & Country Hotel & Convention Center, San Diego, California / Aydin Vector Division has developed and manufactured an airborne, high shock, wideband FM/FM telemetry system for Saab Missiles AB in Sweden. This system was presented in the ITC Proceedings of 1988, Volume XXIV, pp 71-84 (Ref [1]). Three such systems were supplied. Saab Missiles AB also awarded Aydin Vector Division with an additional order for a larger number of high shock, computer based, specially designed, miniature PCM/FM airborne telemetry systems. These systems were developed, manufactured and supplied to Saab Missiles AB, and have been extensively and successfully used in the Swedish program. The PCM/FM telemetry package described in this paper was used for the system testing and the firing trials program of a mortar projectile, where the measurement requirements included micro processor interfaces, as well as a high amount of analog and bi-level data channels. The paper covers the specifications of the PCM/FM system mentioned above, the concept that was used to meet these specifications, the system’s mechanical and electrical design, the packaging technique and some of the test results.
42

A DSP IMPLEMENTED DIGITAL FM MULTIPLEXING SYSTEM

Rosenthal, Glenn K. 11 1900 (has links)
International Telemetering Conference Proceedings / November 04-07, 1991 / Riviera Hotel and Convention Center, Las Vegas, Nevada / Recent advancements in high-speed Digital Signal Processing (DSP) concepts and devices permit digital hardware implementation of relatively high-frequency signal processing, which formerly required analog circuitry. Systems utilizing this technology can provide a high degree of software programmability; improved reproducibility, reliability, and maintainability; immunity to temperature induced drift errors; and compare favorably in cost to their analog counterparts. This paper describes the DSP implementation of a software programmable, digital frequency multiplexed FM system providing up to 4 output multiplexes, containing up to 36 subcarrier channels extending up to 4 MHZ, and accommodating modulating frequencies up to 64 kHz. System overall design goals and the implementation of these goals are presented.
43

TECHNOLOGY ON TRANSMITTING A SINGLE SUPER FAST WAVEFORM SIGNAL IN REAL-TIME

Honglin, Yang, Yonghui, Yang 10 1900 (has links)
International Telemetering Conference Proceedings / October 26-29, 1998 / Town & Country Resort Hotel and Convention Center, San Diego, California / This paper describes the technology on transmitting a single super fast waveform signal in real-time and introduces the general situation of the telemetry transmitter in vehicle. The equipment is a FM system in view of RF frequency, it is a pulse system in view of RF power. This equipment can transfer not only super fast waveform signals but also slowly varying conventional telemetry signals. The design is very novel. It is a multi-usage telemetry transmitter in vehicle.
44

Bandwidth-efficient pilot-symbol-aided techniques for fading estimation in multipath fading channels

吳萬雄, Ng, Man-hung. January 2001 (has links)
published_or_final_version / Electrical and Electronic Engineering / Doctoral / Doctor of Philosophy
45

Frequency dependent digital compensation in DSP based FM modulators.

Tuthill, John D. January 2000 (has links)
This thesis reports original work on digital compensation for frequency dependent transfer characteristics and errors in digital PAM/CPFSK (Pulse Amplitude Modulation/Continuous Phase Frequency Shift Keying) quadrature modulators.A particularly flexible and cost effective approach to the implementation of the base-band section of a radio transmitter is to synthesise base-band signals digitally using a DSP (Digital Signal Processor). This approach is limited, however, by the transfer characteristics and errors in the implementation of practical analogue sub-systems. These practical limitations result in undesirable in-band frequency-dependent shaping of the transmitted signals. In the case of FM (Frequency Modulation) signals, this leads to the generation of unwanted side-lobes in the transmitted RF signal spectrum that interfere with signals in adjacent frequency channels. This results in the transmitted signal failing to meet transmission standards requirements.The digital compensation techniques developed and presented in this thesis allow the reduction of undesirable in-band frequency-dependent signal shaping. It is shown that this enables strict requirements on the spectral emissions from the FM transmitter to be met using a flexible and cost effective DSP based modulator system.The contributions of the thesis are in three primary areas:(i) The development of a structure for frequency dependent digital compensation.(ii) The formulation and solution of an optimisation problem that allows the free parameters within the structure to be determined such that effective reduction of unwanted in-band frequency-dependent signal shaping is achieved.(iii) The development of techniques that allow the digital compensation procedure to be successfully implemented on a practical DSP platform.The new digital compensation structure that is proposed uses two digital FIR (Finite ++ / Impulse Response) filters in the digital base-band section of the quadrature modulator: one in the in-phase (I) channel and one in the quadrature (Q) channel. The tap-weights of the FIR filters are determined by solving two optimisation problems: one for each channel. The optimisation problems are formulated using a new approach that ensures that the degrees of freedom in the optimisation i.e., the FIR filter tap-weights, are used effectively to meet the objective of reducing in-band frequency-dependent signal shaping in analogue sub-systems further down the transmission path.A characterisation of the solutions to the optimisation problems enables the identification of techniques that need to be adopted to successfully implement the proposed digital compensation on a practical DSP-based system.The digital compensation technique is demonstrated by implementing and testing the technique on a DSP platform. The results of experimental studies are presented which clearly demonstrate that the digital compensation technique leads to substantial reductions in adjacent channel interference.
46

The design of delta-sigma modulators for multi-standard RF receivers

Liu, Mingliang 09 June 2003 (has links)
The transition from second-generation (2G) to third-generation (3G) wireless cellular and cordless telephone systems requires multi-standard adaptability in a single RF receiver equipment. An important answer to this request is the use of Delta-Sigma modulators for IF-to-baseband conversion, which will satisfy the dynamic range requirements for digital signal processing, and at the same time, add adaptability and programmability to the characteristics of a RF receiver. This thesis addresses the issues of designing a Delta-Sigma modulator for a multi-standard wireless receiver. A single-loop third-order modulator topology suitable for low power and high integration multi-standard receiver design is proposed. The trade-offs in the modulator design are also presented and explained. The modulator, which has been implemented as a part of a monolithic receiver chip, will be fabricated in a standard 0.35-��m CMOS process. The post-layout simulation results have verified the outcomes of system analysis. / Graduation date: 2004
47

Nonlinear least-squares filtering and frequency modulation

January 1960 (has links)
Arthur Dickson Hause. / "August 25, 1960." Issued also as a thesis, M.I.T. Dept. of Electrical Engineering, August 22, 1960. / Bibliography: p.48-49. / Army Signal Corps Contract DA36-039-sc-78108. Dept. of the Army Task 3-99-20-001 and Project 3-99-00-000.
48

FM weaker-signal suppression with narrow-band limiters

January 1960 (has links)
Robert J. McLaughlin. / "This report is based on a thesis submitted to the Department of Electrical Engineering, M.I.T., June 1958, in partial fulfillment of the requirements for the degree of Master of Science." / Bibliography: p. 33. / Army Signal Corps Contract DA36-039-sc-78108. Dept. of the Army Task 3-99-20-001 and Project 3-99-00-000.
49

Nonlinear properties of FM limiters

January 1959 (has links)
Luiz C. Bahiana. / "May 29, 1959." Based on a thesis, M.I.T. Dept. of Electrical Engineering, January 20, 1958. / Bibliography: p. 47. / Army Signal Corps Contract DA36-039-sc-78108. Dept. of the Army Task 3-99-20-001 and Project 3-99-00-000.
50

Theory of low-distortion transmission of FM signals through linear systems

January 1957 (has links)
Elie J. Baghdady. / "July 30, 1957." / Bibliography: p. 48. / U.S. Army Signal Corps Contract No. DA36-039-sc-64637 Dept. of the Army Task 3-99-06-108 Project 3-99-00-100

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