DSP - how to remove mean. How to add a delayed signal?

[svensl]

Dear all,

I have a few questions on DSP that I would like to get of my chest.
Please consider a 1-bit digital output of a sigma delta modulator as an example.
1) How can I digitally remove any dc (mean) components in the 1-bit stream?
2) I also would like to delay the output by N samples (N is quite large) and then add to its un-delayed version. What would be an efficient way to implement this?

Thanks for any feedback.

 

[thuvu]

You need a digital filter a guess. Do you hve problems creating it?

 

[svensl]

What kind of filter would I need that elimintates the dc term but won't distrub the signal close to dc? A differentiator won't do. Is there not a different way without using a filter?

thanks,