def __init__(self, interp, taps=None, atten=100):
gr.hier_block2.__init__(self, "pfb_interpolator_ccf",
gr.io_signature(1, 1, gr.sizeof_gr_complex),
gr.io_signature(1, 1, gr.sizeof_gr_complex))
self._interp = interp
self._taps = taps
if (taps is not None) and (len(taps) > 0):
self._taps = taps
else:
# Create a filter that covers the full bandwidth of the input signal
bw = 0.4
tb = 0.2
ripple = 0.99
made = False
while not made:
try:
self._taps = optfir.low_pass(self._interp, self._interp, 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 = filter.pfb_interpolator_ccf(self._interp, self._taps)
self.connect(self, self.pfb)
self.connect(self.pfb, self)
def __init__(self, interp, taps=None, atten=100):
gr.hier_block2.__init__(self, "pfb_interpolator_ccf",
gr.io_signature(1, 1, gr.sizeof_gr_complex),
gr.io_signature(1, 1, gr.sizeof_gr_complex))
self._interp = interp
self._taps = taps
if (taps is not None) and (len(taps) > 0):
self._taps = taps
else:
# Create a filter that covers the full bandwidth of the input signal
bw = 0.4
tb = 0.2
ripple = 0.99
made = False
while not made:
try:
self._taps = optfir.low_pass(self._interp, self._interp, 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 = filter.pfb_interpolator_ccf(self._interp, self._taps)
self.connect(self, self.pfb)
self.connect(self.pfb, self)
def test_000(self):
N = 1000 # number of samples to use
M = 5 # Number of channels
fs = 1000 # baseband sampling rate
ifs = M*fs # input samp rate to decimator
#taps = filter.firdes.low_pass_2(M, ifs, fs/2, fs/10,
# attenuation_dB=80,
# window=filter.firdes.WIN_BLACKMAN_hARRIS)
from pfb_interpolator_taps import taps
freq = 100
signal = gr.sig_source_c(fs, gr.GR_COS_WAVE, freq, 1)
head = gr.head(gr.sizeof_gr_complex, N)
pfb = filter.pfb_interpolator_ccf(M, taps)
snk = gr.vector_sink_c()
self.tb.connect(signal, head, pfb)
self.tb.connect(pfb, snk)
self.tb.run()
Ntest = 50
L = len(snk.data())
t = map(lambda x: float(x)/ifs, xrange(L))
# Create known data as complex sinusoids at freq
# of the channel at the interpolated rate.
phase = 0.62833
expected_data = map(lambda x: math.cos(2.*math.pi*freq*x+phase) + \
1j*math.sin(2.*math.pi*freq*x+phase), t)
dst_data = snk.data()
self.assertComplexTuplesAlmostEqual(expected_data[-Ntest:], dst_data[-Ntest:], 4)
