In an IEEE 802.11 wireless system, a wireless STA is configured to signal a plurality of different spatial stream encoding values to a second STA device in a wireless personal area network in accordance with IEEE 802.11 protocol by generating a signaling physical layer protocol data unit (PPDU) which comprises a dedicated user information field which directly or indirectly identifies a plurality of different modulation and coding selection (MCS) values or different modulation orders used to encode different spatial streams from a plurality of spatial streams Nss used in a beamformed MIMO transmission of a data packet for each scheduled user of the signaling PPDU.