Instrumentation Problems Encountered Making Man-Made Electromagnetic Noise Measurements for Predicting Communication System Performance

One of the factors involved in communication system performance is the electromagnetic interference environment (broad-band radiated electronic noise). Attempts are often made to use commercially available radio-frequency interference field intensity meters for these measurements. Measurements made with these instruments are of limited use since detector functions like peak and quasi-peak are not useful parameters in statistical communication theory. It is recommended, instead, that rms voltage be measured simultaneously with average voltage and average logarithm of the voltage. These latter three parameters may be used to infer the amplitude probability distribution, which is a required statistic for predicting the performance of communication systems. Data are given on dynamic range requirements for accurate measurement of these statistical parameters for a given man-made noise sample. An Appendix contains several hardware solutions to the problems posed in this paper.