Dear Shaunwag, that depens on the bandwidth you want to let through your filter, but typically, use something like
firdes.low_pass(1.0, samp_rate, 25e3, 25e3) which will build a tap vector for you; the arguments (in this order) are: 1. gain in passband 2. sampling rate 3. cutoff frequency of pass band in Hz 4. transition with between pass- and stop band Generally, you should have a bit of fun with the tool that you as "gr_filter_design"; it gives you a good feeling for what kind of filters make sense (e.g. when you try to filter out 25kHz out of a 10MHz input stream with a single FIR filter using the method described above, you'd get a ~1000 taps filter. And no noone should expect their CPU to compute that in real time.), and where you can allow your filter to have a bit more of "slack". Best regards, Marcus On 06/12/2015 03:42 PM, shaunwang wrote: > Thank you so much. Tom > > Could you please tell me what a typical value in tabs is? > > > > -- > View this message in context: > http://gnuradio.4.n7.nabble.com/terminate-called-after-throwing-an-instance-of-std-invalid-argument-tp54156p54164.html > Sent from the GnuRadio mailing list archive at Nabble.com. > > _______________________________________________ > Discuss-gnuradio mailing list > [email protected] > https://lists.gnu.org/mailman/listinfo/discuss-gnuradio _______________________________________________ Discuss-gnuradio mailing list [email protected] https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
