A Flexible Window Function for Spectral Analysis [DSP Tips and Tricks]

摘要

Regarding window functions used in spectral analysis, the most important performance measures are 3-dB bandwidth and sidelobe attenuation. For many window functions, Hanning and Hamming for example, we have no control over a window's 3-dB bandwidth and sidelobe attenuation for a given window length. For other window functions¿Kaiser, Gaussian, and Chebyshev "we can reduce those windows" 3-dB bandwidth to get improved spectral resolution. However, with these later window functions (what we refer to as "conventional windows"), spectral resolution improvement comes at the expense of sidelobe attenuation reduction that degrades our ability to avoid undesirable spectral leakage. Likewise we can increase those windows sidelobe attenuation, but only by sacrificing desirable spectral resolution. This article describes a novel window function that enables us to control both its 3-dB bandwidth (spectral resolution) and sidelobe attenuation (spectral leakage) independently.