clear all;
close all;
clc;
re_freq = 1/50; %relative frequency of the signal
len_sig = [0 : 499 ]; %length of the signal
dig_after = [0 : 10]; % No. of Digits after decimal points to be retained
%loop through the different values of q
for num = 1 : length(dig_after)
sgnx = cos(2*pi*re_freq*len_sig); %our signal equation
pw_sig = sum(abs( sgnx ).^2)/length( sgnx ); %calculating the power of the signal
sgnx_q = round(sgnx*10^dig_after(num))/10^dig_after(num); %quantizing the signal
sgnx_err = sgnx - sgnx_q;
%calculating the error between the signals
pw_err = sum(abs(sgnx_err).^2)/length(sgnx_err); %calculating the power of the error signal
SQNR(num) = 10*log10(pw_sig/pw_err); %calculating SQNR
end
figure,
plot(dig_after,SQNR);
xlabel('Significant Digits');
ylabel('SQNR (dB)');
ylabel('SQNR (dB)');
xlim([dig_after(1) dig_after(end)]);