In an example of multi-user wireless communications, an access point may send a downlink frame, including a common information field and multiple per user information fields, to multiple stations. The common information field and the per user information fields are located in a payload section of the downlink frame. The common information field includes information common to all of the stations. Each per user information field may have information specific to its corresponding station. Some or all of the stations may generate and transmit their respective uplink frames based on the common information field and their respective per user information field(s) included in the downlink frame. The downlink frame may be a trigger frame such as a multi-user block acknowledgment request (MU BAR) frame. The uplink frames may be block acknowledgment or acknowledgment (BA or ACK) frames. Other methods, apparatus, and computer-readable media are also disclosed.