Hi I'm trying to execute the below code to observe the impact of noise on the FFT of the signal. Even if i'm increasing noise content there is little impact on the signal's Spectrum. Why ?

Question

Deepak kumar 2018-9-5

0
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此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/417638-hi-i-m-trying-to-execute-the-below-code-to-observe-the-impact-of-noise-on-the-fft-of-the-signal-eve

评论： Deepak kumar 2018-9-26

if true
  % clc
clear all
close all
A=10;
F=2; %Signal Frequency
fs=50*F; %Sampling Frequency
t=0:1/fs:49*1/F; %Time Duration
%Original Signal
x=A*sin(2*pi*F*t);
subplot(511)
plot(t,x)
xlabel('time')
ylabel('X')
title('Original Signal')
%Adding Noise to the signal
n=8*randn(1,length(x));
y=x+n;
N=length(y);
subplot(512)
plot(t,y)
axis([0 inf -10 10])
xlabel('time')
ylabel('y')
title('Signal with Noise')
%Spectral Analysis of Noisy Signal
L=length(y);
NFFT=2^nextpow2(L);
y_fft=1/NFFT*abs(fft(y,NFFT));
f=fs/2*linspace(0,1,NFFT/2+1);
subplot(513)
plot(f,y_fft(1:length(f)))
xlabel('f')
ylabel('y_fft')
title('FFT of Noisy Signal')
end