On Mon, Jan 05, 2009 at 01:44:53PM -0800, Matt Ettus wrote: > Ryan Pape wrote: >> All: >> I'm currently trying to extract a relatively small number of >> narrowband channels out of about 10mhz. With USRP1, I can get two >> channels easily by using both sets of DDCs. In some instances, I can >> successfully use a filterbank, however at 12.5khz channels, I quickly >> run out of horsepower if I don't keep the decimation high enough, >> which does not always let me cover the swath of RF I need. Are there >> any other possibilities with the new USRP2 hardware to implement more >> DDCs in the firmware to do more of this work on the USRP side? Any >> other thoughts in general? > > You could implement more DDCs in the USRP2, but it makes more sense to > use filterbanks in software. It may take something more complicated > than a straight forward filterbank across the whole bandwidth. You > might want to do it in a few steps. For example, do a filterbank to get > you 16 channels of ~500 kHz apiece, and then do smaller filterbanks on > only those 500kHz bands have signals of interest in them. > > Matt
The filterbank in the tree was done quick and dirty. There's lots of room for improvement. (e.g., coalescing many of the intermediate blocks.) Eric _______________________________________________ Discuss-gnuradio mailing list [email protected] http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
