Hi Guys,
I am finding issues in SNR calculation for my Simulink model and the model given in Screier toolbox.A  pdf file is attached with the SNR figures and the model i have used

Specifications for my simulink model:

Amplitude= 0.8
Samples per period= 1170
Sample time= 10^-6
Frequency=2*pi*854.49 Hz

a,g,b,c have been calculated for CIFB model as:

H = synthesizeNTF(2,256,0,2);
[a,g,b,c] = realizeNTF(H,'CIFB')
a =
  0.4721    1.2361
g =
   0
b =
 0.4721    1.2361    1.0000
c =
   1     1

Matlab code for SNR calculation:
OSR = 256;
H = synthesizeNTF(2,OSR,0,2);
N = 8192; fB = ceil(N/(2*OSR));
f=7;
u = 0.8*sin(2*pi*f/N*[0:N-1]);
v = simulateDSM(u,H);
%%
t = 0:1000;
stairs(t, u(t+1),'g');
hold on;
stairs(t,v(t+1),'b');
axis([0 200 -1.2 1.2]);
ylabel('u, v');
%%
spec=fft(v.*ds_hann(N))/(N/4);
%figure
plot(linspace(0,0.5,N/2+1), ...
dbv(spec(1:N/2+1)));
axis([0 0.5 -120 0]);
grid on;
ylabel('dBFS/NBW')
snr=calculateSNR(spec(1:fB),f);
s=sprintf('SNR = %4.1fdB\n',snr)
text(0.25,-90,s);
s=sprintf('NBW=%7.5f',1.5/N);
text(0.25, -110, s);


Problem is that SNR for my model does'nt scale with OSR and also significantly smaller than theoretical one....

All sorts of suggestions are solicited....

Thanks and Regards,
Sourav

Hi Sourav,

Would you please show the plots in log scale for x-axis? And it is good to attach it as picture?

Yawei