Remove noisy channels out of an array

Hello,

How to remove few noisy channels out of 64 channels?

Thanks

Answer 1

[Tarunbir Gambhir]

Assuming that you are trying to remove signals with high noise from a group of channels. You can use the snr function in MATLAB to calculate the Signal-to-Noise ratio for all the channels. This will help you decide and remove the channels that are high in noise.

If you just want noise reduction, then I suggest that you refer to the MATLAB documentation on Signal Smoothing.

[Saad Alqahtani]

Thanks for answering my question. But I'm looking for a code.I've already knew what channles I need to remove. So, basicly I'm trying to remove few rows out of a matrix. Thanks!

[Tarunbir Gambhir]

You can refer the following code for removal of rows from a matrix.

t = linspace(0,1,1000); 
% creating a sample signal 
signal = chirp(t); 
% creating a matrix with 20 channels of the above signal with 5db of noise 
channelArray = awgn(repmat(signal,20,1),5); 
% size of channelArray here is 20x1000 
% Lets assume that channel number 3, 7, 13, and 17 needs to be removed 
remove = [3, 7, 13,17]; 
channelArray(remove,:) = []; 
% size of channelArray after channel removal is 16x1000  

For further information, you may go through the MATLAB documentation on Matrices and Arrays.

[Saad Alqahtani]

Thanks