Designs a multirate FIR filter impulse response \(h[n]\) using the Kaiser window method.

Parameters:¶

interpolation: int¶

The interpolation rate \(P\).

decimation: int = 1¶

The decimation rate \(Q\).

polyphase_order: int = 23¶

The order of each polyphase filter. Must be odd, such that the filter lengths are even.

atten: float = 80¶

The stopband attenuation \(A_{\text{stop}}\) in dB.

Returns:¶

The multirate filter impulse response \(h[n]\).

References¶

• fred harris, Multirate Signal Processing for Communication Systems, Chapter 7: Resampling Filters.

• https://www.mathworks.com/help/dsp/ref/designmultiratefir.html

Examples¶

Design a multirate FIR filter for rational resampling by 11/3.

In [1]: h = sdr.design_multirate_fir(11, 3)

In [2]: plt.figure(); \
   ...: sdr.plot.impulse_response(h);
   ...: 

In [3]: plt.figure(); \
   ...: sdr.plot.magnitude_response(h);
   ...: