Disclosed in some examples are devices (e.g., APs, STAs, and the like), methods, and machine readable mediums which provide for proper channel estimation and frame reception in Uplink MU-MIMO systems by changing the way transmission parameters from the VHT-SIG-A are communicated to the recipients in the preamble. The transmission parameters contained in the VHT-SIG-A field may be communicated to the STAs in advance of the MU-MIMO transmissions. In other examples the transmission parameters contained in the VHT-SIG-A field may be moved to locations in the preamble that come after the VHT-STF and VHT-LTF so that the transmission parameters may be decoded.