The capture of the weaker of two co-channel frequency-modulated signals

Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering, 1960.Includes bibliographical references (leaf 215).by Joseph Michael Gutwein.M.S

F. M. Capture Performance - Characterization and Measurement

International Telemetering Conference Proceedings / May 18-20, 1965 / Sheraton Park Hotel, Washington DCThe effects of interference and capture in FM reception are reviewed for the purpose of determining the basis for characterizing and measuring the capture performance of FM receivers. Capture performance criteria and performance measurement techniques are proposed for application to FM telemetry receiver evaluation.International Foundation for TelemeteringProceedings from the International Telemetering Conference are made available by the International Foundation for Telemetering and the University of Arizona Libraries. Visit http://www.telemetry.org/index.php/contact-us if you have questions about items in this collection

A Double Sideband-Quadrature Carrier Multiplex Telemetry System

International Telemetering Conference Proceedings / October 08-11, 1968 / Ambassador Hotel, Los Angeles, CaliforniaA novel FDM telemetry technique was developed consisting of a double sideband-quadrature carrier multiplexing system (DSB-QCM). Each subchannel in the DSB-QCM system carries two completely overlapping DSB data signals, one double-sideband modulated on the subcarrier itself, and the other on a quadrature version of the subcarrier. Demodulation with cophasal and quadrature subcarriers enables simultaneous data extraction from each channel within acceptable distortion levels. The feasibility and practicability of such a DSB-QCM telemetry system is discussed in this paper. Crosstalk levels between the quadrature multiplexed channels were measured and guardband requirements between adjacent channels were assessed for a modem comprised of three pairs of DSB-QCM channels. Crosstalk levels between uniformly loaded DSB -QCM channels were below 2% and guardband requirements equivalent to conventional DSB systems were observed. The DSB-QCM performance was also examined as a function of input SNR with two competing subcarrier synchronization methods. Subcarrier synchronization by means of synthesized reference tones coherently derived from a single pilot was demonstrated to be superior in The presence of noise to a channel reference approach in which each data channel must synchronize its own subcarrier. The major conclusion from this investigation is that DSB-QCM/FM telemetry combines the advantages of both SSB/FM and DSB/FM by accommodating as many data channels as SSB/FM but with low distortion data processing and the dc data response characteristic of DSB/FM.International Foundation for TelemeteringProceedings from the International Telemetering Conference are made available by the International Foundation for Telemetering and the University of Arizona Libraries. Visit http://www.telemetry.org/index.php/contact-us if you have questions about items in this collection