How do you determine the size of taps? How much of a difference does setting the transition width from 1MHz to 10MHz make?
Generally, the wider the transition width, the fewer taps.
You can use the "firdes" functions, which is what the low-pass filter blocks call in gnuradio, then take their output into a variable and
have another variable be len(filter).
On Tue, Nov 19, 2013 at 6:40 PM, Marcus D. Leech <mle...@ripnet.com <mailto:mle...@ripnet.com>> wrote:I really appreciate the detailed explanation. I tried running gr_filter_design last night and it asked me to install SciPy, which I did not feel like doing at that time. I will try using 1MHz for my band, which may help get rid of the real-time running issue. Again, I appreciate your help with this matter.Let's say you get a filter that's, oh, I dunno, 100 taps long. That filter has to process every sample, so, that's 5e7 X 100 taps, orroughly 5e9 FLOP/second. Just for that one filter. And your flow-graph is likely doing other things *and* it's having to get samples all the way through your network or USB stacks into the application layer as well, call that 100 instructions/sample. So, that's 5e7 x 100 = 5e9 OPS/second just to get your samples into the application. You're going to burn-up the cycles on your CPU pretty quickly at 50Msps, even for doing "trivial" things.-- Marcus LeechPrincipal Investigator Shirleys Bay Radio Astronomy Consortium http://www.sbrac.org _________________________________________________ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org <mailto:Discuss-gnuradio@gnu.org> https://lists.gnu.org/mailman/__listinfo/discuss-gnuradio <https://lists.gnu.org/mailman/listinfo/discuss-gnuradio>
-- Marcus Leech Principal Investigator Shirleys Bay Radio Astronomy Consortium http://www.sbrac.org
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