对12bit的AD建模后matlab写程序对其进行FFT，计算SNR并输出频谱图，程序该怎么写？？？急

Question

如题所述

Answer 1

你是不是用simulink将数据输出到workbench？再用matlab计算其SFDR,SNR....等等参数？

最近也在做DAC的动态校准的东西，就把代码给你吧。我注释了一部分，你根据自己的需要自己改回来。

%load ScopeData;
dynamic_data=ScopeData.signals.values;

data_size=size(dynamic_data);

N=max(data_size);

sample_number=input('输入采样点数：');

if sample_number>N

display('样本数据数量不够,请检查')

else data=dynamic_data(1:sample_number);

N=sample_number;

end

F_samples=input('输入采样频率:');

Mean_code=mean(data);

V=data-Mean_code;

V=V.*hanning(N);

dout_spect=fft(V);

dout_dB=20*log10(abs(dout_spect));

max_dB=max(dout_dB(1:N/2));

x=(0:N/2-1).*F_samples/N;

y=dout_dB(1:N/2)-max_dB;

figure(1)

plot(x,y);

axis([0,F_samples/2,-120,0]);

grid off;

title('FFT图');

xlabel('模拟输入频率（Hz）');

ylabel('幅值（dB）');

F_in=find(dout_dB(1:N/2)==max_dB);

span=max(round(N/200),5);

spanh=2;

spectp=(abs(dout_spect)).*(abs(dout_spect));

Pdc=sum(spectp(1:span));

%Ps=sum(spectp(F_in-span:F_in+span));

F_harmonic=[];

P_harmonic=[];

for har_number=1:10

tone=rem((har_number*(F_in-1)+1)/N,1);

if tone>0.5

tone=1-tone;

end

F_harmonic=[F_harmonic tone];

har_peak=max(spectp(round(tone*N)-spanh:round(tone*N)+spanh));

har_bin=find(spectp(round(tone*N)-spanh:round(tone*N)+spanh)==har_peak);

har_bin=har_bin+round(tone*N)-spanh-1;

P_harmonic=[P_harmonic sum(spectp(har_bin-1:har_bin+1))];

end

disp(F_harmonic)

disp(P_harmonic)
%
% Pd=sum(P_harmonic(2:5));
%
% Pn=sum(spectp(1:N/2))-Pdc-Ps-Pd;

format;

% SNR=10*log10(Ps/Pn)
%
% SINAD=10*log10(Ps/(Pn+Pd))

SFDR=10*log10(P_harmonic(1)/max(P_harmonic(2:5)))

% THD=10*log10(Pd/P_harmonic(1))
%
% ENOB=(SINAD-1.76)/6.02