Noise Measurement with Matlab

The present code is a Matlab function that provides:

Plotting of:
– the signal in the time domain;
– the Power Spectral Density of the signal.
Displaying of:
– the average PSD before the A- or C- weighting;
– the average PSD after A- or C- weighting;
– the output noise (by TrueRMS Voltmeter) before A- or C- weighting;
– the output noise (by TrueRMS Voltmeter) after A- or C- weighting.

Two examples are given in order to clarify the usage of the function. For convenience, the input and output arguments are given at the beginning of the function.

The code is based on the theory described in the references.

References:

[1] A. Kay. Operational Amplifier Noise: Techniques and Tips for Analyzing and Reducing Noise (Chapter 5). Oxford, Newnes, 2012.
[2] Design Response of Weighting Networks for Acoustical Measurements ANSI S1.42-2001. Washington, American National Standards Institute, 2001.
[3] Electroacoustics Sound Level Meters Part 1: Specifications IEC 61672-1:2002. Geneva, International Electrotechnical Commission, 2002.
[4] G. Heinzel, A. Rudiger, R. Schilling. Spectrum and spectral density estimation by the Discrete Fourier transform (DFT), including a comprehensive list of window functions and some new flat-top windows. Hannover, Max-Planck-Institut für Gravitationsphysik, 2002.
[5] Хр. Живомиров. Измерване на някои шумови параметри на усилвателите с приложение на Matlab. Трети международен научен конгрес „50 год. Технически университет – Варна”, 4 – 6 Октомври 2012, Варна. Third International Scientific Congress Proceedings, ISBN 978-954-20-0551-3, Vol. 2, pp. 32-37, 2012.