On Wed, Nov 27, 2019 at 6:22 PM Joseph Gwinn <joegw...@comcast.net> wrote: > in two batches. The window functions largely eliminate the splice > error due to the FFT, which is fact splices each batch into a circle, > causing a discontinuity at the splice. If the window function is very > small at the splice, there is little discontinuity power sprayed into > innocent FFT bins. > > In radar, Taylor windows are used, as well as Dolph-Chebyshev if very > low sidelobes are needed.
Related to but distinct from low-sidelobe window functions are _sidelobeless_ windows, which I think may be particularly useful in control-loop applications like PLLs. The gaussian window is obviously sidelobeless, but it has infinite support so it's not useful. But it turns out that there exist finite windows that are completely sidelobeless (a fourier transform of their kernel is monotone). A triangular window convolved with a truncated gaussian window is sidelobeless (with an appropriate choice in parameters), as is a hann-poisson window. While working on the problem of sinusodial modelling ( https://arxiv.org/abs/1602.05900 ), which is essentially the same problem as PLL tracking tones in a noisy signal, I found sidelobeless windows to work much better than even low sidelobe windows like Dolph-Chebyshev ... but I never found a lot of coverage in the literature. _______________________________________________ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
