A method for signal processing in a receiver includes receiving in the receiver a Multi-User Multiple-Input Multiple-Output (MU-MIMO) signal. The MU-MIMO signal includes at least a first signal, which is precoded using a first precoding scheme and is addressed to the receiver, and a second signal, which is precoded using a second precoding scheme. An average error rate achievable in decoding the first signal in the presence of the second signal is computed. The average error rate is computed over a set of possible choices of the second precoding scheme. The first precoding scheme is selected from among a plurality of available precoding schemes so as to satisfy a criterion defined over the average error rate. The receiver sends feedback to a transmitter transmitting the first signal. The feedback depends on the selected first precoding scheme and causes the transmitter to control transmission of the first signal.