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git-svn-id: http://moon:8086/svn/vhdl/trunk@1469 cc03376c-175c-47c8-b038-4cd826a8556b
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jens
2021-03-22 20:34:53 +00:00
parent 44047cd580
commit d9427ed6e3
2 changed files with 151 additions and 0 deletions
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lib/radio/nco/ghdl/tb_mix_results.m
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% Read data
function tb_mix_results()
fa = 100.0;
f = textread('freq.txt')*1E-6
R = 128;
fa_dec = fa/R
N_pfir = 63;
I_in = textread('i_in.txt')';
I_out = textread('i_out.txt')';
Q_out = textread('q_out.txt')';
N= length(I_out)
N_fft = N
N_fft2 = fix(N_fft/2);
fft_y2 = 2/N_fft*abs(fft(I_out(1:N_fft).*hann(N_fft)'));
[i, v] = get_maxpur(fft_y2, fa, f);
max_spur_freq = (i*fa/N_fft);
max_spur_value = 20*log10(v);
fft_y3 = 2/N_fft*abs(fft(I_in(1:N_fft).*hann(N_fft)'));
[i, v] = get_maxpur(fft_y3, fa, f);
max_ditherd_spur_freq = (i*fa/N_fft);
max_ditherd_spur_value = 20*log10(v);
I_out_dec = cic_filter(R, 1, 3, I_out);
Q_out_dec = cic_filter(R, 1, 3, Q_out);
N_dec = length(I_out_dec)-2*N_pfir;
N_fft_dec = N_dec
N_fft2_dec = N_fft_dec/2;
fft_y2_dec = 2/N_fft_dec*abs(fft(I_out_dec(2*N_pfir+1:N_fft_dec+2*N_pfir).*hann(N_fft_dec)'));
pfir_b = sinc(0.1*(-(N_pfir-1)/2:1:(N_pfir)/2));
pfir_b = pfir_b/sum(pfir_b).*blackman(N_pfir)';
I_out_dec_pfir = filter(pfir_b, 1, I_out_dec);
Q_out_dec_pfir = filter(pfir_b, 1, Q_out_dec);
fft_y2_dec_pfir = 2/N_fft_dec*abs(fft(I_out_dec_pfir(2*N_pfir+1:N_fft_dec+2*N_pfir).*hann(N_fft_dec)'));
% Output
close all;
plot(fa/(R*N_fft_dec)*(0:N_fft2_dec),20*log10(fft_y2_dec(1:N_fft2_dec+1)), '-', fa/(R*N_fft_dec)*(0:N_fft2_dec),20*log10(fft_y2_dec_pfir(1:N_fft2_dec+1)), '-'); grid;
figure;
plot(1:length(I_out_dec_pfir), I_out_dec_pfir, 1:length(Q_out_dec_pfir), Q_out_dec_pfir); grid;
figure;
freqz(pfir_b, 1, 1000);
figure;
plot(pfir_b); grid;
figure;
subplot(2,1,1)
plot(fa/N_fft*(0:N_fft2),20*log10(fft_y2(1:N_fft2+1)), '-', fa/N_fft*(0:N_fft2), max_spur_value*ones(1,N_fft2+1), 'r-', [max_spur_freq], [max_spur_value], 'ro'); grid;
spur_legend = sprintf('Max. spur %.1fdB at %.3fMHz', max_spur_value, max_spur_freq);
legend('With dithering', spur_legend);
legend('No dithering', spur_legend);
title('Table');
ylabel('dB');
xlabel('f/MHz');
axis([0 fa/2 -140 0]);
subplot(2,1,2)
plot(fa/N_fft*(0:N_fft2),20*log10(fft_y3(1:N_fft2+1)), '-', fa/N_fft*(0:N_fft2), max_ditherd_spur_value*ones(1,N_fft2+1), 'r-', [max_ditherd_spur_freq], [max_ditherd_spur_value], 'ro'); grid;
spur_legend = sprintf('Max. spur %.1fdB at %.3fMHz', max_ditherd_spur_value, max_ditherd_spur_freq);
legend('With dithering', spur_legend);
title('Table');
ylabel('dB');
xlabel('f/MHz');
axis([0 fa/2 -140 0]);
plot(1:N, I_out, 1:N, Q_out); grid;
function [max_i, max_v] = get_maxpur(spec, fa, f)
max_v = 0;
max_i = 0;
for ii=1:fix(length(spec)/2+1),
fi = ii*fa/length(spec);
dfi = fi - f;
if abs(dfi) > 0.005*f
if spec(ii) > max_v
max_v = spec(ii);
max_i = ii-1;
end
end;
end;
lib/radio/nco/ghdl/tb_nco_results.m
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% Read data
function tb_nco_results(nbins)
fa = 100.0;
f = textread('freq.txt')*1E-6
I_ud = textread('q_ud.txt')';
I_d = textread('q_d.txt')';
LFSR = textread('lfsr.txt');
N= length(I_ud);
N_fft = min(16384, N);
N_fft2 = fix(N_fft/2);
fft_y2 = 2/N_fft*abs(fft(I_ud(1:N_fft).*hann(N_fft)'));
fft_y3 = 2/N_fft*abs(fft(I_d(1:N_fft).*hann(N_fft)'));
[i, v] = get_maxpur(fft_y2, fa, f);
max_spur_freq = (i*fa/N_fft);
max_spur_value = 20*log10(v);
[i, v] = get_maxpur(fft_y3, fa, f);
max_ditherd_spur_freq = (i*fa/N_fft);
max_ditherd_spur_value = 20*log10(v);
% Output
close all;
subplot(2,1,1)
plot(fa/N_fft*(0:N_fft2),20*log10(fft_y2(1:N_fft2+1)), '-', fa/N_fft*(0:N_fft2), max_spur_value*ones(1,N_fft2+1), 'r-', [max_spur_freq], [max_spur_value], 'ro'); grid;
spur_legend = sprintf('Max. spur %.1fdB at %.1fMHz', max_spur_value, max_spur_freq);
legend('With dithering', spur_legend);
legend('No dithering', spur_legend);
title('Table');
ylabel('dB');
xlabel('f/MHz');
axis([0 fa/2 -140 0]);
subplot(2,1,2)
plot(fa/N_fft*(0:N_fft2),20*log10(fft_y3(1:N_fft2+1)), '-', fa/N_fft*(0:N_fft2), max_ditherd_spur_value*ones(1,N_fft2+1), 'r-', [max_ditherd_spur_freq], [max_ditherd_spur_value], 'ro'); grid;
spur_legend = sprintf('Max. spur %.1fdB at %.1fMHz', max_ditherd_spur_value, max_ditherd_spur_freq);
legend('With dithering', spur_legend);
title('Table');
ylabel('dB');
xlabel('f/MHz');
axis([0 fa/2 -140 0]);
figure;
hist(LFSR, nbins)
function [max_i, max_v] = get_maxpur(spec, fa, f)
max_v = 0;
max_i = 0;
for ii=1:fix(length(spec)/2+1),
fi = ii*fa/length(spec);
dfi = fi - f;
if abs(dfi) > 0.05*f
if spec(ii) > max_v
max_v = spec(ii);
max_i = ii;
end
end;
end;