#Spectral resolution calculator windows

In order to implement the 512 bandpass filters efficiently, a polyphase analysis filter bank (a.k.a. Filter Bank-Based Spectrum Estimationįor this example, 512 different bandpass filters need to be used to get the same resolution afforded by the rectangular window. The main idea is to divide the signal into different frequency bins using a filter bank and computing the average power of each subband signal. Instead of using averaged modified periodograms (Welch's method), a higher resolution estimate can be achieved by using a filter bank approach that emulates how analog spectrum analyzers work.

#Spectral resolution calculator windows

Parameterizable windows such as Kaiser allow to control the tradeoff by changing the window parameter. Hann windows provide good sidelobe attenuation at the expense of lower frequency resolution.

Poor sidelobe attenuation can result in spectral components being buried by the windowing operation and thus is undesirable. Rectangular windows provide the highest resolution but very poor (~14 dB) sidelobe attenuation. The classical tradeoff with different windows is one of resolution vs. When windowing is used on the time-domain segment as is the case with modified periodograms, the type of window used also affects the resolution. Resolution depends on the length of the time-domain segment used to compute the spectrum. Resolution in this context refers to the ability to distinguish between two spectral components that lie in the vicinity of each other.