How to design a DFE equalizer?

Hi,
I want to know how to design a DFE equalizer. In some text books, it
gives the formular but I don't know how to calculate the correlation
and cross correlation matrix. On the other hand, some material gives
formular when one have the received training samples. My situation is
that I know the channel impulse response (of course, this is a
assumption). How to design a DFE with the criterion of MMSE? And
further how to design a DFE in the MIMO? In MIMO, we want to use DFE to
detect the highest S/N signal first, then the second... Any comments
are highly appreciated. Thanks.