Preamble selection for simultaneous transmissions in wireless local area network (wlan) systems

A device comprising:

• a processor configured to:
• determine a number of data streams associated with a high efficiency transmission, wherein the determined number of data streams is between 2 and 8;
• select a number of symbols to be one of 2, 4, 6, or 8, wherein the selected number of symbols is equal to the determined number of data streams or a next higher number than the determined number of data streams;
• and
• send a high efficiency long training field (LTF) using the selected number of symbols, wherein being configured to send the high efficiency LTF is based on a function of a subcarrier index comprising a relationship where a subcarrier is an element of subchannels.

A method for transmission associated with multi-user multiple input multiple-output (MU MIMO) comprising:

• determining a number of data streams associated with a high efficiency transmission, wherein the determined number of data streams is between 2 and 8;
• selecting a number of symbols to be one of 2, 4, 6, or 8, wherein the selected number of symbols is equal to the determined number of data streams or a next higher number than the determined number of data streams;
• and
• sending a high efficiency long training field (LTF) using the selected number of symbols, wherein sending the high efficiency LTF is based on a function of a subcarrier index comprising a relationship where a subcarrier is an element of subchannels.