Uplink multi-user multiple-in, multiple-out (UL MU-MIMO) transmissions involve coordinating or scheduling stations communications with an access point. Methods and systems for scheduling UL MU-MIMO transmissions provide selection of stations permitted to communicate during the UL MU-MIMO transmission. One method includes transmitting a first trigger message that requests each station to transmit a second message to the access point. The method also includes receiving the second messages from responding stations and estimating, based on the second messages, one or more parameters for each responding station. The method further includes generating a schedule for the stations to transmit data to the access point and transmitting a second trigger message to the stations, the second trigger message identifying the schedule and the stations that are scheduled to transmit UL data to the access point according to the schedule. The method also includes receiving data during the UL MU-MIMO transmission opportunity from the stations.