diff options
| -rw-r--r-- | gnuradio-core/src/python/gnuradio/optfir.py | 25 | ||||
| -rwxr-xr-x | gr-utils/src/python/gr_filter_design.py | 27 |
2 files changed, 48 insertions, 4 deletions
diff --git a/gnuradio-core/src/python/gnuradio/optfir.py b/gnuradio-core/src/python/gnuradio/optfir.py index 06a0eea61..ad5743287 100644 --- a/gnuradio-core/src/python/gnuradio/optfir.py +++ b/gnuradio-core/src/python/gnuradio/optfir.py @@ -27,7 +27,7 @@ For a great intro to how all this stuff works, see section 6.6 of and Barrie W. Jervis, Adison-Wesley, 1993. ISBN 0-201-54413-X. ''' -import math +import math, cmath from gnuradio import gr remez = gr.remez @@ -75,6 +75,29 @@ def band_pass (gain, Fs, freq_sb1, freq_pb1, freq_pb2, freq_sb2, taps = gr.remez (n + nextra_taps, fo, ao, w, "bandpass") return taps + +## Builds a band pass filter with complex taps by making an LPF and +# spinning it up to the right center frequency +# @param gain Filter gain in the passband (linear) +# @param Fs Sampling rate (sps) +# @param freq1 End of stop band (in Hz) +# @param freq2 Start of pass band (in Hz) +# @param passband_ripple_db Pass band ripple in dB (should be small, < 1) +# @param stopband_atten_db Stop band attenuation in dB (should be large, >= 60) +# @param nextra_taps Extra taps to use in the filter (default=2) +def complex_band_pass (gain, Fs, freq_sb1, freq_pb1, freq_pb2, freq_sb2, + passband_ripple_db, stopband_atten_db, + nextra_taps=2): + center_freq = (freq_pb2 + freq_pb1) / 2.0 + lp_pb = (freq_pb2 - center_freq)/1.0 + lp_sb = freq_sb2 - center_freq + lptaps = low_pass(gain, Fs, lp_pb, lp_sb, passband_ripple_db, + stopband_atten_db, nextra_taps) + spinner = [cmath.exp(2j*cmath.pi*center_freq/Fs*i) for i in xrange(len(lptaps))] + taps = [s*t for s,t in zip(spinner, lptaps)] + return taps + + ## Builds a high pass filter. # @param gain Filter gain in the passband (linear) # @param Fs Sampling rate (sps) diff --git a/gr-utils/src/python/gr_filter_design.py b/gr-utils/src/python/gr_filter_design.py index 0579d0fe2..4aa59360f 100755 --- a/gr-utils/src/python/gr_filter_design.py +++ b/gr-utils/src/python/gr_filter_design.py @@ -15,8 +15,6 @@ from gnuradio import gr, blks2, eng_notation from scipy import fftpack from pyqt_filter import Ui_MainWindow -from pyqt_filter_firlpf import Ui_firlpfForm -from pyqt_filter_firhpf import Ui_firhpfForm class gr_plot_filter(QtGui.QMainWindow): def __init__(self, qapp, options): @@ -196,7 +194,8 @@ class gr_plot_filter(QtGui.QMainWindow): if(winstr == "Equiripple"): designer = {"Low Pass" : self.design_opt_lpf, "Band Pass" : self.design_opt_bpf, - "High Pass" : self.design_opt_hpf} + "Complex Band Pass" : self.design_opt_cbpf, + "High Pass" : self.design_opt_hpf} taps,r = designer[ftype](fs, gain) else: @@ -381,6 +380,28 @@ class gr_plot_filter(QtGui.QMainWindow): else: return ([],r) + def design_opt_cbpf(self, fs, gain, wintype=None): + ret = True + pb1,r = self.gui.startofBpfPassBandEdit.text().toDouble() + ret = r and ret + pb2,r = self.gui.endofBpfPassBandEdit.text().toDouble() + ret = r and ret + tb,r = self.gui.bpfTransitionEdit.text().toDouble() + ret = r and ret + atten,r = self.gui.bpfStopBandAttenEdit.text().toDouble() + ret = r and ret + ripple,r = self.gui.bpfPassBandRippleEdit.text().toDouble() + ret = r and ret + + if(r): + sb1 = pb1 - tb + sb2 = pb2 + tb + taps = blks2.optfir.complex_band_pass(gain, fs, sb1, pb1, pb2, sb2, + ripple, atten) + return (taps,r) + else: + return ([],r) + def design_opt_hpf(self, fs, gain, wintype=None): ret = True sb,r = self.gui.endofHpfStopBandEdit.text().toDouble() |