Abstract—In the multi-user MIMO uplink channel, the presence of multiple receive antennas enables the base station to serve a number of users simultaneously, thus increasing overall system throughput. In practice, users have to be scheduled instead of being served all at once. In this work, a novel scheduling metric is proposed based on ergodic sum capacity. A low-SNR Taylor series of the capacity expression is combined with a receiver-correlation channel model to obtain a robust measure of spatial compatibility. Long-term channel knowledge at the base station is sufficient for metric evaluation, which significantly reduces the amount of required channel sounding, compared to previously proposed schemes.