diff options
| -rw-r--r-- | gnuradio-core/src/python/gnuradio/blks2impl/pfb_arb_resampler.py | 53 |
1 files changed, 53 insertions, 0 deletions
diff --git a/gnuradio-core/src/python/gnuradio/blks2impl/pfb_arb_resampler.py b/gnuradio-core/src/python/gnuradio/blks2impl/pfb_arb_resampler.py index 62f40582e..3aadf700b 100644 --- a/gnuradio-core/src/python/gnuradio/blks2impl/pfb_arb_resampler.py +++ b/gnuradio-core/src/python/gnuradio/blks2impl/pfb_arb_resampler.py @@ -73,3 +73,56 @@ class pfb_arb_resampler_ccf(gr.hier_block2): def set_rate(self, rate): self.pfb.set_rate(rate) + + +class pfb_arb_resampler_fff(gr.hier_block2): + ''' + Convenience wrapper for the polyphase filterbank arbitrary resampler. + + The block takes a single float stream in and outputs a single float + stream out. As such, it requires no extra glue to handle the input/output + streams. This block is provided to be consistent with the interface to the + other PFB block. + ''' + def __init__(self, rate, taps=None, flt_size=32, atten=100): + gr.hier_block2.__init__(self, "pfb_arb_resampler_fff", + gr.io_signature(1, 1, gr.sizeof_float), # Input signature + gr.io_signature(1, 1, gr.sizeof_float)) # Output signature + + self._rate = rate + self._size = flt_size + + if taps is not None: + self._taps = taps + else: + # Create a filter that covers the full bandwidth of the input signal + bw = 0.4 + tb = 0.2 + ripple = 0.1 + #self._taps = gr.firdes.low_pass_2(self._size, self._size, bw, tb, atten) + made = False + while not made: + try: + self._taps = optfir.low_pass(self._size, self._size, bw, bw+tb, ripple, atten) + made = True + except RuntimeError: + ripple += 0.01 + made = False + print("Warning: set ripple to %.4f dB. If this is a problem, adjust the attenuation or create your own filter taps." % (ripple)) + + # Build in an exit strategy; if we've come this far, it ain't working. + if(ripple >= 1.0): + raise RuntimeError("optfir could not generate an appropriate filter.") + + self.pfb = gr.pfb_arb_resampler_fff(self._rate, self._taps, self._size) + #print "PFB has %d taps\n" % (len(self._taps),) + + self.connect(self, self.pfb) + self.connect(self.pfb, self) + + # Note -- set_taps not implemented in base class yet + def set_taps(self, taps): + self.pfb.set_taps(taps) + + def set_rate(self, rate): + self.pfb.set_rate(rate) |