-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 Johnathan Corgan wrote: > For the receive side, you can use a blks.analysis_filterbank to turn a > wideband signal with N carriers into N baseband channels equally spaced. > > Then you can attach demodulators to these output ports. > > This is demonstrated in the gr-pager code: > > http://gnuradio.org/trac/browser/gnuradio/trunk/gr-pager/src/usrp_flex_band.py > > Here we capture 1 MHz of USRP spectrum, then create 40 baseband output > channels at 25 KHz each, then attach 40 decoder blocks to these outputs.
In this example (and indeed, in the code for the analysis_filterbank), we divide a 1MHz band exactly into 25 kHz channels. However, the channels at the edge will be attenuated (cite: Matt's email of yesterday 12:11 AM PST). I therefore oversampled the desired passband by 33%, which causes the resulting wideband signal to not divide evenly into channel-sized chunks. If I do some sort of 3/4 resampling should the passband quality suffer? Thanks! Dan -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.6 (GNU/Linux) Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org iD8DBQFG3wbey9GYuuMoUJ4RAvvUAJ9W9PeZG+mTA1Nlwl3YGZgdG8NrzACbB+Ue yznc+0nwbfB9J0APeR0mcFw= =5v5I -----END PGP SIGNATURE----- _______________________________________________ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
