Tom Rondeau said the following on 10/14/2011 12:01 PM:
John, You've almost got it right except for the taps. The "taps" parameter is the FIR taps of the prototype filter, which then gets partitioned among the N channels of the channelizer. While there is no example in GRC readily available, you can look at the channelize.py example in: gnuradio-examples/python/pfb/ Specifically, line 49 is where the filter taps are created. Notice that the sample rate is the sample rate at the input to the channelizer while the bandwidth and transition width are defined for the channel bandwidths. This makes a fairly long filter that is then split up between the N channels of the PFB.
Thanks, Tom. So it appears that you use a firdes.lowpass type function in the taps setting. I've done that and I now get somewhat more sane results on the output FFT.
However, I'm still seeing massive underruns when I assume the same sample rate as the input. Is there a decimation going on (i.e., output_rate = input_rate/num_channels or something like that)?
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