Proceedings of the 2022 IEEE International Symposium on Electromagnetic Compatibility, Signal & Power Integrity, Spokane, WA, August 2-5, 2022

Estimating the Local Mean Voltage of a Radio Signal in a Mobile Channel

Robert T. Johnk; John J. Lemmon

Abstract: This paper examines the estimation of the local mean voltage of a radio signal in a Rayleigh fast-fading environment. We focus on the statistical uncertainties of local voltage averages obtained by both integrating the voltage envelope of a specified spatial interval and averaging over a set of discrete spatial samples. We derive new analytical expressions of the variances of both discrete and continuous averaging for selected spatial intervals. We also give recommendations for averaging intervals and sample spacing to achieve a ±1 dB spreading factor. We provide important new results for the variance of discrete averaging with new insight gained on separations required for uncorrelated samples. One significant finding of this work is that criteria in the published literature are incorrect and underestimate the variance. We support these findings with an experimental validation of our variance expressions using laboratory fading simulator measurements and sample statistics.

Keywords: autocorrelation; propagation; fast signal fading; correlation; path loss; continuous wave (CW); Rayleigh; time series; vector signal analyzer; channel sounder; coverage factor; discrete averge; I/Q envelope; local mean; Lee 40 wavelength criterion; sampling; standard deviation; spreading factor; variance

To request a reprint of this report, contact:

Lilli Segre, Publications Officer
Institute for Telecommunication Sciences
(303) 497-3572
LSegre@ntia.gov

For technical information concerning this report, contact:

Robert T. Johnk
Institute for Telecommunication Sciences
(303) 497-3737
bjohnk@ntia.doc.gov

Disclaimer: Certain commercial equipment, components, and software may be identified in this report to specify adequately the technical aspects of the reported results. In no case does such identification imply recommendation or endorsement by the National Telecommunications and Information Administration, nor does it imply that the equipment or software identified is necessarily the best available for the particular application or uses.

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