Removing DC component of a signal

[cc12]

removing dc signal

Hi,

I want to normalize a signal and generate the power spectrum in matlab SP tool box. I used following command to normalize the signal.

=x1-mean(x1);

But, still there is very big DC components appears in the power spectrum. Can you please explain me how to eliminate this? Here I have attached a piece of my signal.

 

[Communications_Engineer]

power in dc component

low pass filter?

 

[cc12]

power of signal dc component

Can you please explain me little bit about using a lowpass filter? I have sent a sample of my data.

Best
cc12

 

[FvM]

spectrum dc component

=x1-mean(x1); is by definition exactly removing the DC component. However, after applying a window or cutting out part of the data, you'll see a non-zero DCcomponent again. It can't be "very big", absolutely.

 

[doraemon]

power dc component

Hello!

To be accurate, mean(x) is a low pass filter.
x-mean(x) is a high pass filter.

The problem of moving average is that you cannot get a very sharp
response. Look here for more detail.
If you want a good filter quite simple to implement, sharp, etc..., you may
consider a 2nd order IIR.

Dora.

Hi,

I want to normalize a signal and generate the power spectrum in matlab SP tool box. I used following command to normalize the signal.

=x1-mean(x1);

But, still there is very big DC components appears in the power spectrum. Can you please explain me how to eliminate this? Here I have attached a piece of my signal.