In the project no-OS-2014_R2, it removes a known DC offset and takes a removal filter actions(in the file ad_dcfilter.v). I have seen the web page I/Q Correction [Analog Devices Wiki]. It just says that the data needs to be removed the DC offset, But it does not mention the removal filter.
my questions are:
1. Why does it need a removal filter?
2. How is the removal filter process the data by it's coefficient?