Hi,
Given a SNR value in dB I want to add noise to my below narrow pulsed signal .
Fs=200e6;
Fs=200e6;t=t=0:1/Fs:255/Fs;Fc=50e6;tau1=400e-9;tau2=80e-9;Req_SNR=10; % in dB
Sn= sin(2*pi*Fc*t).*exp(-4*pi*(((t-tau1)/tau2).^2));
I am following below steps to add noise to signal.
Pow_Sn=sum(St.^2); % compute signal power
rn=randn(1, size(t)); rn_power=sum(rn.^2);Noise_amp=sqrt(Pow_Sn./((10^(Req_SNR/10)))); %
Noise=rn.*Noise_amp; Sn_Noise=Sn+Noise;SNR_measured=snr(Sn_Noise,Noise); % to test.
My questions are as followings:
- Is Signal power computation correct.
- Is noise generation method correct.
- Why SNR_measured do not equal to Req_SNR.
Note: randn outout are not in range of -3.25 to 3.02
.
Best Answer