System and method for tuning transmission parameters based on estimated ratio between a signal to an estimated interference plus noise (SINR) of a user, in a multiple-user multiple-input multiple-output (MU-MIMO) communication system, the method including obtaining channel state information (CSI) related to a channel from an access point (AP) to users that participate in a next MU-MIMO transmission, wherein the AP, and the users pertain to the MU-MIMO communication system, obtaining error coefficients related to errors related to channel-ageing and to estimation noise of the CSI, and calculating the estimated SINR, wherein the estimated interference is related to power of the other users and to the estimated channel magnitude the user u, and to the error coefficients, wherein the estimated channel magnitude is derived from the CSI.