Generate Specific noise(i.e. 60 or 70 Hz) Matlab

I want to add some artificially noise of specific frequency. Can someone help?

Answer 1

[Ameer Hamza]

If you just want to add a specific frequency noise in you signal then try this

f = 5;
fn = 60;

t = linspace(0, 1, 200);
y = sin(2*pi*f*t);
yn = 0.2*sin(2*pi*fn*t);
y = y + yn;
plot(t, y)

Check the fft() of the signal and you will see peaks at 5Hz (original signal) and 60Hz (noise)

Fs = 1/(t(2)-t(1));
fv = linspace(0, 1, numel(t))*Fs;
mag = abs(fft(y));
plot(fv, mag);

[Utpal Mozumder]

Thanks a lot

[Utpal Mozumder]

Is it possible to shift the phase of the original signal with this noise?

Answer 2

[KSSV]

L = 60 ;                                       % Length in sec
f   = 60 ;                                     % Frequency in Hz
Fs  = 10000 ;                                 % Sampling Frequency
t   = linspace(0, L, Fs*len);                 % time Vector

x = sin(2*pi*f*t);                         
noise = x + 0.1*randn(size(x));