multirate_helper¶
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sk_dsp_comm.multirate_helper.freqz_resp(b, a=[1], mode='dB', fs=1.0, Npts=1024, fsize=(6, 4))[source]¶ A method for displaying digital filter frequency response magnitude, phase, and group delay. A plot is produced using matplotlib
freq_resp(self,mode = ‘dB’,Npts = 1024)
A method for displaying the filter frequency response magnitude, phase, and group delay. A plot is produced using matplotlib
freqz_resp(b,a=[1],mode = ‘dB’,Npts = 1024,fsize=(6,4))
b = ndarray of numerator coefficients a = ndarray of denominator coefficents- mode = display mode: ‘dB’ magnitude, ‘phase’ in radians, or
- ‘groupdelay_s’ in samples and ‘groupdelay_t’ in sec, all versus frequency in Hz
Npts = number of points to plot; defult is 1024
fsize = figure size; defult is (6,4) inches
Mark Wickert, January 2015
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class
sk_dsp_comm.multirate_helper.multirate_FIR(b)[source]¶ A simple class for encapsulating FIR filtering, or FIR upsample/ filter, or FIR filter/downsample operations used in modeling a comm system. Objects of this class will hold the required filter coefficients once an object is instantiated. Frequency response and the pole zero plot can also be plotted using supplied class methods.
Mark Wickert March 2017
Methods
dn(x[, M_change])Downsample and filter the signal filter(x)Filter the signal up(x[, L_change])Upsample and filter the signal zplane([auto_scale, size, detect_mult, tol])Plot the poles and zeros of the FIR filter in the z-plane freq_resp
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class
sk_dsp_comm.multirate_helper.multirate_IIR(sos)[source]¶ A simple class for encapsulating IIR filtering, or IIR upsample/ filter, or IIR filter/downsample operations used in modeling a comm system. Objects of this class will hold the required filter coefficients once an object is instantiated. Frequency response and the pole zero plot can also be plotted using supplied class methods. For added robustness to floating point quantization all filtering is done using the scipy.signal cascade of second-order sections filter method y = sosfilter(sos,x).
Mark Wickert March 2017
Methods
dn(x[, M_change])Downsample and filter the signal filter(x)Filter the signal using second-order sections freq_resp([mode, fs, ylim])Frequency response plot up(x[, L_change])Upsample and filter the signal zplane([auto_scale, size, detect_mult, tol])Plot the poles and zeros of the FIR filter in the z-plane
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class
sk_dsp_comm.multirate_helper.rate_change(M_change=12, fcutoff=0.9, N_filt_order=8, ftype='butter')[source]¶ A simple class for encapsulating the upsample/filter and filter/downsample operations used in modeling a comm system. Objects of this class will hold the required filter coefficients once an object is instantiated.
Mark Wickert February 2015
Methods
dn(x)Downsample and filter the signal up(x)Upsample and filter the signal