Embodiments of a high-efficiency WLAN (HEW) master station and method for communicating in a Wireless Network are generally described herein. In some embodiments, the HEW master station comprises a receiver configured to receive an uplink multi-user multiple-input multiple-output (MU-MIMO) transmission from a plurality of scheduled HEW stations. The uplink MU-MIMO transmission may comprise at least an HEW short-training field (STF) (HEW-STF) transmitted by each of the scheduled HEW stations. The HEW-STFs received from the HEW stations are distinguishable. The master station may process the HEW-STFs received from the scheduled HEW stations to set receiver gain for reception of UL-MIMO data from the scheduled HEW stations. In some embodiments, a single automatic gain control (AGC) setting may be determined from the combined HEW-STF resulting in improved receiver performance in UL MU-MIMO.