Abstract: Disclosed apparatuses obtain real time performance measurements and adaptively select MIMO antennas to improve MIMO antenna performance under given conditions. A correlation estimator determines an approximation of instantaneous antenna correlation values. One method includes obtaining a CQI measurement for a first antenna and a second antenna of a mobile device. The method proceeds by determining a composite CQI for the two antennas and estimating the antenna correlation for the first antenna and second antenna using the composite CQI. The method may further include performing a table lookup operation in a CQI table that maps composite CQI including at least a first and second MIMO stream to coding rates. The method may further include obtaining an SNR measurement for the first antenna and the second antenna of the mobile device, and estimating the antenna correlation for the first antenna and second antenna using the composite CQI and the SNR measurement.