Long training field sequence construction

A method for facilitating wireless communication, the method comprising:

• selecting, by a wireless device based on a bandwidth of a frame, a high efficiency long training field (HE-LTF) sequence for the frame;
• selecting an HE-LTF transmission mode from one of a 4× HE-LTF mode, a 2× HE-LTF mode, and a 1× HE-LTF mode;
• transmitting, by the wireless device to a set of stations, only a set of allocated subcarriers of the HE-LTF sequence for the frame, wherein each subcarrier in the set of allocated subcarriers is allocated to a station in the set of stations for the frame;
• and
• transmitting, by the wireless device to the set of stations, a set of additional fields of the frame using the set of allocated subcarriers and a set of unallocated subcarriers, the set of additional fields including a legacy short training field (L-STF), a legacy long training field (L-LTF), a legacy signaling field (L-SIG), a high efficiency signaling A field (HE-SIG-A), and a high efficiency short training field (HE-STF),
• wherein transmitting of the HE-LTF sequence for the frame uses only one or more of the set of allocated subcarriers, and none of the unallocated subcarriers.

A non-transitory machine-readable storage medium that stores instructions, which when executed by one or more processors of a wireless device, cause the wireless device to:

• select, based on a bandwidth of a frame, a high efficiency long training field (HE-LTF) sequence for the frame;
• select an HE-LTF transmission mode from one of a 4× HE-LTF mode, a 2× HE-LTF mode, and a 1× HE-LTF mode;
• transmit, to a set of stations, only a set of allocated subcarriers of the HE-LTF sequence for the frame, wherein each subcarrier in the set of allocated subcarriers is allocated to a station in the set of stations for the frame;
• and
• transmit, to the set of stations, a set of additional fields of the frame using the set of allocated subcarriers and a set of unallocated subcarriers, the set of additional fields includes a legacy short training field (L-STF), a legacy long training field (L-LTF), a legacy signaling field (L-SIG), a high efficiency signaling A field (HE-SIG-A), and a high efficiency short training field (HE-STF),
• wherein the transmission of the HE-LTF sequence for the frame uses only one or more of the set of allocated subcarriers, and none of the unallocated subcarriers.