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Changes to Matlab model

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This commit is contained in:
Imants Pulkstenis
2020-04-04 16:06:23 +03:00
parent 5f98346282
commit ad59f40a9d
8 changed files with 67 additions and 1065 deletions
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matlab/myfft4_real_imag.m
+66 -93
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@@ -5,75 +5,51 @@
clear; % clears all previus values from memory
clc; % clear command window
fs = 44100; % samplinf freq.
fftLength=256; % windowlength
fftLength=2^9; % windowlength
stage_num = log2(fftLength);
Wn_word = 12; % signed fixed point lenght for Wn (fraction is word-2)
samp_word = 8; % word lenght of samped signal (fraction is word-2)
w_bits = 10; % signed fixed point integer bit lenght
f_bits = 10; % signed fixed point integer bit lenght for calculations
while 1 % Checking for correct "fftLength"-Wondow length value
if ~mod(stage_num,1)==0
error('"fftLength"-Wondow length value must be a numer: 2^x= : 2, 4, 8, 16, 32,...');
break
else
% continue working if value is correct
% signal frequencies
max = 2048 - 1 ;
f1 = 430;
a1 = 0;
f2 = 4300;
a2 = 0;
f3 = 8000;
a3 = max/2;
% calculating signals
comp1 = a1 * sin(2*pi*f1*[0:1/fs:1]);
comp2 = a2 * sin(2*pi*f2*[0:1/fs:1]);
comp3 = a3 * sin(2*pi*f3*[0:1/fs:1]);
Length = length(comp3);
data = comp1 + comp2 + comp3; % creates vector from 3 sin functions
%data = comp3;
% Plot shifting to center
bin_vals = [0 : fftLength-1];
N_2 = ceil(fftLength/2);
fax_kHz = (bin_vals-N_2)*fs/fftLength/1000;
freq3 = ceil(-(fftLength)/2:1:(fftLength)/2).*(fs/fftLength)/1000;
figure(1) % plots separete sin functions
hold off,
%plot ( comp1, '-');
hold on;
%plot ( comp2, '-');
plot (comp3, '-')
xlim([1 50]), grid minor,;
title('Separete SIN functions')
ylabel('magnitude'), xlabel('time')
hold off;
% reading input audio file
% audio samples are from matlab examples
% load handel.mat
% filename = 'handel.wav';
% load gong.mat;
filename = 'gong.wav';
% audiowrite(filename,y,Fs);
[y,fs] = audioread(filename);
data = sfi(y, samp_word, samp_word-2);
m = 7; % alow select section of signal for FFT
data_cut = data(fftLength*m+1:fftLength*m+fftLength);
%sound(data.double,fs);
figure(2) % plots signal for fft
plot (data), grid minor,;
xlim([1 50])
plot (data_cut), grid minor,
% xlim([fftLength*m+1 fftLength*m+fftLength])
title('Signal for FFT analysis FFT')
ylabel('magnitude'), xlabel('time')
bin_vals = [0 : fftLength-1];
figure(3) % plots resultinf fft from Matlab functions
ft = fft(data,fftLength);
ft = fft(data_cut.double,fftLength);
ft1 = fftshift(ft);
ftMag = abs(ft1);
plot (fax_kHz,ftMag), grid minor,
plot (bin_vals,ftMag), grid minor,
title('Linear Magnitude FFT')
ylabel('magnitude'), xlabel('kHz')
ylabel('magnitude'), xlabel(' ')
figure(4) % plots resultinf fft(in dB) from Matlab functions
ft = fft(data,fftLength);
ft1 = fftshift(ft);
ftMag = abs(ft1(1:fftLength));
plot (fax_kHz,20*log10(ftMag)), grid minor,
title('dB Magnitude')
ylabel('dB'), xlabel('kHz')
% figure(4) % plots resultinf fft(in dB) from Matlab functions
% ft = fft(data.double,fftLength);
% ft1 = fftshift(ft);
% ftMag = abs(ft1(1:fftLength));
% plot (bin_vals,20*log10(ftMag)), grid minor,
% title('dB Magnitude')
% ylabel('dB'), xlabel(' ')
%% Data preparation for FFT
@@ -97,67 +73,64 @@ imag_n_sfi = zeros(bits+1,fftLength);
%% Starting stages
for st = 0 : stage_num;
for st = 0 : stage_num
if st == 0
for tmp=1:fftLength;
stage(st+1,tmp) = data(rev_bit_dec(tmp)+1);
real_n(st+1,tmp) = data(rev_bit_dec(tmp)+1);
for tmp=1:fftLength
stage(st+1,tmp) = data_cut(rev_bit_dec(tmp)+1);
real_n(st+1,tmp) = data_cut(rev_bit_dec(tmp)+1);
real_n_sfi(st+1,tmp) = sfi(real_n(st+1,tmp),f_bits + w_bits ,f_bits);
end
else st > 0;
for n = 1 : fftLength/2;
for n = 1 : fftLength/2
Wn(n) = exp(-j * (n-1) * 2 * pi/ 2^(st) );
Wr(n) = real(Wn(n));
Wi(n) = imag(Wn(n));
% Wr(n) = real(Wn(n));
% Wi(n) = imag(Wn(n));
Wr(n) = sfi(real(Wn(n)),Wn_word,Wn_word-2);
Wi(n) = sfi(imag(Wn(n)),Wn_word,Wn_word-2);
end
for i = 1 : 2^st : fftLength;
for k = 0 : 2^(st-1)-1;
for i = 1 : 2^st : fftLength
for k = 0 : 2^(st-1)-1
% Even
stage(st+1,i+k) = stage(st,i+k) + Wn(k+1)*stage(st,i+k+2^(st-1));
real_n(st+1,i+k) = real_n(st,i+k) + Wr(k+1)*real_n(st,i+k+2^(st-1)) - Wi(k+1)*imag_n(st,i+k+2^(st-1));
imag_n(st+1,i+k) = imag_n(st,i+k) + Wi(k+1)*real_n(st,i+k+2^(st-1)) + + Wr(k+1)*imag_n(st,i+k+2^(st-1));
real_n(st+1,i+k) = real_n_sfi(st,i+k) + Wr(k+1)*real_n_sfi(st,i+k+2^(st-1)) - Wi(k+1)*imag_n_sfi(st,i+k+2^(st-1));
imag_n(st+1,i+k) = imag_n_sfi(st,i+k) + Wi(k+1)*real_n_sfi(st,i+k+2^(st-1)) + Wr(k+1)*imag_n_sfi(st,i+k+2^(st-1));
real_n_sfi(st+1,i+k) = sfi(real_n(st+1,i+k),f_bits + w_bits,f_bits);
imag_n_sfi(st+1,i+k) = sfi(imag_n(st+1,i+k),f_bits + w_bits,f_bits);
% Odd
stage(st+1,i+k+2^(st-1)) = stage(st,i+k) - Wn(k+1)*stage(st,i+k+2^(st-1));
real_n(st+1,i+k+2^(st-1)) = real_n(st,i+k) - Wr(k+1)*real_n(st,i+k+2^(st-1)) + Wi(k+1)*imag_n(st,i+k+2^(st-1));
imag_n(st+1,i+k+2^(st-1)) = imag_n(st,i+k) - Wi(k+1)*real_n(st,i+k+2^(st-1)) - Wr(k+1)*imag_n(st,i+k+2^(st-1));
real_n(st+1,i+k+2^(st-1)) = real_n_sfi(st,i+k) - Wr(k+1)*real_n_sfi(st,i+k+2^(st-1)) + Wi(k+1)*imag_n_sfi(st,i+k+2^(st-1));
imag_n(st+1,i+k+2^(st-1)) = imag_n_sfi(st,i+k) - Wi(k+1)*real_n_sfi(st,i+k+2^(st-1)) - Wr(k+1)*imag_n_sfi(st,i+k+2^(st-1));
real_n_sfi(st+1,i+k+2^(st-1)) = sfi(real_n(st+1,i+k+2^(st-1)),f_bits + w_bits,f_bits);
imag_n_sfi(st+1,i+k+2^(st-1)) = sfi(imag_n(st+1,i+k+2^(st-1)),f_bits + w_bits,f_bits);
end
end
end
end
%% Constructing signed fixed-point numeric objects
for n = 1 : fftLength/2;
Wr_sfi(n) = sfi(real(Wn(n)),16);
Wi_sfi(n) = sfi(imag(Wn(n)),16);
end
for n = 1 : fftLength;
for k = 1 : st + 1
real_n_sfi(k,n) = sfi(real_n(k,n),24);
imag_n_sfi(k,n) = sfi(imag_n(k,n),24);
end
end
%% Plotting out
% for slowly result plotting uncomment pause
figure(5)
for i = 1 : bits + 1;
%for i = 1 : bits + 1;
for i = bits+1 : bits + 1
%plot( fax_kHz, abs( fftshift( real_n(i, :) + j.*imag_n(i,:) ) ) ),
plot( fax_kHz, abs( fftshift( stage(i,:) ) ) ),
grid minor, title('Linear Magnitude FFT'), ylabel('magnitude'), xlabel('kHz');
plot( bin_vals, abs( fftshift( stage(i,:) ) ) ),
grid minor, title('Linear Magnitude FFT'), ylabel('magnitude'), xlabel(' ');
%pause(1);
end
figure(6)
for i = 1 : bits + 1;
plot( fax_kHz, abs( fftshift( real_n(i, :) + j.*imag_n(i,:) ) ) ),
grid minor, title('Linear Magnitude FFT, ploted from Real + Imag'), ylabel('magnitude'), xlabel('kHz');
%for i = 1 : bits + 1;
for i = bits+1 : bits + 1
plot( bin_vals, abs( fftshift( real_n_sfi(i, :) + j.*imag_n_sfi(i,:) ) ) ),
grid minor, title('Linear Magnitude FFT, ploted from Real + Imag'), ylabel('magnitude'), xlabel(' ');
%plot( fax_kHz, abs( fftshift( stage(i,:) ) ) ), grid minor,;
%pause(1);
end
break
end
end
figure(7)
dif = abs( fftshift( stage(bits+1,:) ) ) - abs( fftshift( real_n_sfi(bits+1, :) + j.*imag_n_sfi(bits+1,:) ) ) ;
plot( bin_vals, dif )
grid minor, title('Difference in plots'), ylabel('diff magnitude'), xlabel(' ');