Method for operating a wireless network, wherein at least one MIMO (Multiple Input Multiple Output) group of different stations will be constructed by a grouping algorithm based on a grouping metric for providing a MIMO group of different stations addressable simultaneously in space by a base station using MIMO techniques and meeting a definable level of performance quality, the grouping metric being based on an SINR (Signal-to-Interference and Noise Ratio) experienced by each station within the MIMO group. The method includes: computing an SNR (Signal-to-Noise Ratio) that a new station would experience without any interference when added to an existing MIMO group; computing an SINR estimate by correcting the SNR with the sum of spatial correlations between the new and each of the stations already present in the existing MIMO group; and using the SINR estimate for deciding whether the new station can be added to the existing MIMO group.