Arkadi Rafalovich / Mbed 2 deprecated TAU_ReSpeaker_DSP_V02

ReSpeaker DSP V02

Dependencies:   mbed MbedJSONValue

Matlab_Script/ArbMagFilterDesign.txt@14:8a4699aa69b5, 2019-06-20 (annotated)

Committer:
Arkadi
Date:
Thu Jun 20 09:06:46 2019 +0000
Revision:
14:8a4699aa69b5
Parent:
1:574b54755983 
experiments version

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Arkadi 1:574b54755983 1 function [MyFilter, sos, g] = ArbMagFilterDesign(Nb, Na)
Arkadi 1:574b54755983 2 % For iirlpnorm filter description see http://www.mathworks.com/help/dsp/ref/iirlpnorm.html
Arkadi 1:574b54755983 3
Arkadi 1:574b54755983 4 % Nb Numerator Order
Arkadi 1:574b54755983 5 % Na Denominator Order
Arkadi 1:574b54755983 6 P = [2 128]; % P'th norm
Arkadi 1:574b54755983 7 dens = 20; % Density Factor
Arkadi 1:574b54755983 8
Arkadi 1:574b54755983 9 % Frequency Vector - normalized
Arkadi 1:574b54755983 10 % Real frequences = F * (Fs/2) wher Fs is sampling frequency
Arkadi 1:574b54755983 11 F = [0 0.05 0.1 0.15 0.2 0.25 0.3 0.35 0.4 0.45 0.5 0.55 0.6 0.65 0.7 0.75 0.8 0.85 0.9 0.95 1.0];
Arkadi 1:574b54755983 12 % Amplitudas
Arkadi 1:574b54755983 13 A = [0 0 0 0 1 1 1.1 1.1 1.1 1.1 1.2 1.2 1.2 1.2 1.2 1.3 1.3 1.3 1.4 1.4 1.4]; % Amplitude Vector
Arkadi 1:574b54755983 14 % Weights has one entry per frequency point (the same length as f and a) which tells iirlpnorm how
Arkadi 1:574b54755983 15 % much emphasis to put on minimizing the error in the vicinity of each frequency point relative to the other points.
Arkadi 1:574b54755983 16 W = [0.1 0.1 0.1 0.1 ones(1,17)];
Arkadi 1:574b54755983 17 % Frequency Edges, normalized (single band)
Arkadi 1:574b54755983 18 E = [0 1];
Arkadi 1:574b54755983 19
Arkadi 1:574b54755983 20 % Hints
Arkadi 1:574b54755983 21 %
Arkadi 1:574b54755983 22 % This is a weighted least-pth optimization.
Arkadi 1:574b54755983 23 % Check the radii and locations of the poles and zeros for your filter (with zplane function). If the zeros are on the unit circle
Arkadi 1:574b54755983 24 % and the poles are well inside the unit circle, try increasing the order of the numerator or reducing the error weighting in the stopband.
Arkadi 1:574b54755983 25 % Similarly, if several poles have a large radii and the zeros are well inside of the unit circle, try increasing the order
Arkadi 1:574b54755983 26 % of the denominator or reducing the error weighting in the passband.
Arkadi 1:574b54755983 27
Arkadi 1:574b54755983 28 [num,den,err,sos,g] = iirlpnorm(Nb, Na, F, E, A, W, P, {dens});
Arkadi 1:574b54755983 29
Arkadi 1:574b54755983 30 MyFilter = dfilt.df1sos(sos, g);
Arkadi 1:574b54755983 31 end