Citation

Abstract

Simple scaling rules often are used to estimate signal-to-noise ratios (SNRs). For example, one commonly hears that voltage SNR varies as the square root of the number of data samples and linearly as the signal strength. For a variety of reasons, signals often are detected or measured by cross-correlating a small interval of sampled voltage data with a phase model and coherently integrating, followed by incoherently summing the resulting amplitudes over a number of such intervals. When this is done, the usual scaling rules do not always apply and can lead to decidedly incorrect conclusions (an example is given in Section V). This article derives analytic formulas for voltage SNR and some resulting scaling laws when incoherent amplitude sums are performed. In a common low-SNR situation, the correct rule states that voltage SNR varies as the square of the signal strength.

Keywords

siganl to noise ratio SNR incoherent nonlinear nonlinearity voltage SNR

Details

Volume
42-137
Published
May 15, 1999
Pages
1–6
File Size
289.5 KB