Extending the Resolution Limits for Narrow-Band Harmonic and Modal Analysis: A Non-parametric Approach

摘要

Non-parametric FFT-based spectrum analysis is an efficient tool for signal/system characterization in the frequency domain, but it often suffers from an insufficient spectral resolution. Herein we propose methods that improve the spectral physical resolution by redistributing the original spectral information in order to emulate larger time observations. This is accomplished by either non-parametric destructive DFT interpolation or asymmetric time windowing. The proposed methods show to have very good peak discrimination capacity which, together with their low computational complexity, makes them good candidates for narrow-band spectrum analysis in instrumentation.