Adding noise to EEG dataset

Hello I have an EEG dataset loaded into Matlab in Excel format. I want to add a random white noise to the dataset. And I need to convert the output noisy plot again into an excel file. I have attached the Matlab file.

Please suggest me

Thanks

[Kaushik Lakshminarasimhan]

You already managed to add noise. So you just want to know how to write the output to an Excel file?

[dark lion]

Nope I am not getting the output of the noisy signal It is showing an error.

Answer 1

[Kaushik Lakshminarasimhan]

I assume you're getting an error in this line:

X = dataset + 2*randn(size(t));

because dataset is an N x 2 array, whereas 2*randn(size(t)) is 1 x N. Also, you don't want to add noise to time. You need to change it to:

X = [time voltage + A*randn(length(t),1)];

A is the variance of noise, you can set A=1 if you wish. Then write to xls using:

xlswrite('noisyEEG.xls',X);

And if you want to plot it:

plot(X(:,1), X(:,2));

[dark lion]

Still I am unable to get the plot,

It is showing an error like this Matrix dimensions must agree. Error in EEGnoise (line 8) X = [time voltage + 1*randn(length(t),1)];

i will give you the input excel sheet to get a better idea. I have uploaded the text file since excel the comments section is not accepting excel format

[Kaushik Lakshminarasimhan]

The actual length of the signal is a lot longer than the number you use (L=150). Why do you even need the sampling frequency for this? Just do:

dataset=xlsread('input signal.xlsx','sheet1','A1:B770');
t = dataset(:,1);
V = dataset(:,2);
X = [t V+1*randn(length(V),1)];
xlswrite('noisyEEG.xls',X);
plot(X(:,1), X(:,2));

[dark lion]

thank you very much for your Help the data which i have provided you is a raw EEG data I have to add some noise to the data and give the time voltage values as an input to my circuit

Thank you very much!!!

[Kaushik Lakshminarasimhan]

Sounds cool. Good luck!