MIMO antennas basic properties details required URGENT a begginer

Hi all
can any body explain the following properties of MIMO antennas:
Total active reflection coefficient
Isolation
correlation coefficient
group delay
what these are for 2X2 mimo system
and what are their formula
Regards
kartik

how To calculate these using CSt MWS
Total Active Reflection Coefficient (TARC),
Mean Effective Gain (MEG)
XPR is the cross polarizatiion ratio
Antenna Correlation Coefficient