A method includes operating a receiver connected with nr receive antennas to receive uplink signals from K users having nt transmit antennas each; and scheduling which users are to transmit in a same time-frequency-code slot. A particular user pairing configuration is denoted by π within a set of all configurations Π, and scheduling includes expressing mutual information as an additive objective function and maximizing the additive objective function over a particular choice of πεΠ.