Hi, having looked at the current codebase, I find two resamplers suitable for interpolation rates close to 1: gr_fractional_interpolator and gr_pfb_arb_resampler. I can see the latter is newer. Here some questions:
1) When would I use which one, or is gr_fractional_interpolator simply older? I can tell they use different approaches (MMSE vs. linear interpolation), but don't really know what to do with this information :) 2) Concerning gr_fractional_interpolator: The first parameter, called phase_shift in the block definition and is later on referred to as 'mu', seems to be an initial fractional delay. For an infinite stream, why does this matter? It seems to be important, otherwise it would not be the first argument of the block constructor (or is this coincidence? If it's pretty much irrelevant, why not make it second and then give it mu=0 as default value?) 3) Concerning gr_pfb_arb_resampler (I hope I've understood the code correctly): This uses a PFB to get the sampling rate close to what we want, and then linearly interpolates. Isn't this a bit inaccurate? I'm afraid I haven't got Harris' book right here, so I can't check the reference, but perhaps someone who's already used this resampler can share some experience? Thanks a lot for any answers! They'll be greatly appreciated. Cheers, MB -- Karlsruhe Institute of Technology (KIT) Communications Engineering Lab (CEL) Dipl.-Ing. Martin Braun Research Associate Kaiserstraße 12 Building 05.01 76131 Karlsruhe Phone: +49 721 608-3790 Fax: +49 721 608-6071 www.cel.kit.edu KIT -- University of the State of Baden-Württemberg and National Laboratory of the Helmholtz Association
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