MATLAB: How to add a white Noise with rms amplitude of 0.5 v by matlab

MATLABwhite noise

Write an m-file with MATLAB, define a signal with an amplitude of 0.7 V at 20 Hz and an amplitude of 1 V at 50 Hz. Now run a frequency analysis following settings respectively: a) Sampling rate: 1000 Hz, signal length: 1 s b) Same with a) but add white noise of rms-amplitude of 0.5 V

I am confused with (b). How can I solve it ?

Best Answer

The randn function returns normally-distributed random numbers with a mean of 0 and a standard deviation of 1. The standard deviation is essentially the rms value. So multiply your randn vector by 0.5.

Related Solutions

MATLAB: Adding gaussian white noise to data

doc randn

or online

http://www.mathworks.com/help/techdoc/ref/randn.html

MATLAB: I have a sound signal x(n). i want to make a random signal r(n) of the same length but half the magnitude of x(n). How do i make r(n) have half the magnitude of x(n)

Random signals are of course random, so its being exactly half the amplitude is probably not going to be the situation everywhere. You can scale the randn output by multiplying it by the standard deviation you want, so:

signal = ...;                                       % Signal Vector
noise = std(signal)*0.5*randn(size(signal));        % Noise Vector

This scales the noise vector to be 0.5 times the standard deviation of your signal vector. That is probably as close as you can get to what you want to do.

Best Answer

Related Solutions

MATLAB: Adding gaussian white noise to data

MATLAB: I have a sound signal x(n). i want to make a random signal r(n) of the same length but half the magnitude of x(n). How do i make r(n) have half the magnitude of x(n)

Related Question