Threshold Improvement in an FM Subcarrier System
- 1 March 1960
- journal article
- Published by Institute of Electrical and Electronics Engineers (IEEE) in IRE Transactions on Space Electronics and Telemetry
- Vol. SET-6 (1), 25-33
- https://doi.org/10.1109/IRET-SET.1960.5008703
Abstract
The paper is concerned with the causes and characteristics of threshold behavior in pulse-averaging and phase-coherent (``phase-locked loop'') FM subcarrier discriminators. An analytical discussion of the basic elements of each form of discriminator is first presented, leading to a comparison of the devices for input modulation indices of one and five, in the presence of noise. For the first time in the literature, the effect of additional output filtering following the ideal phase-coherent loop is discussed. Finally, the requisite modulation characteristics for an improved threshold in a phase-locked loop discriminator are presented, followed by a brief description of the approaches which may be taken in the design of such a system.Keywords
This publication has 4 references indexed in Scilit:
- Application of the phase-locked loop to telemetry as a discriminator or tracking filterIRE Transactions on Telemetry and Remote Control, 1958
- Design and performance of phase-lock circuits capable of near-optimum performance over a wide range of input signal and noise levelsIRE Transactions on Information Theory, 1955
- Signal-to-Noise Ratios in Band-Pass LimitersJournal of Applied Physics, 1953
- Theory of Frequency-Modulation NoiseProceedings of the IRE, 1948