Patent ID: 9647816
Date: 2017-05-09
CPC Classifications: H04B,H04L

Claim:
1. A transmission method performed in a station, the transmission method comprising: generating a legacy preamble; generating a high efficiency (HE) preamble including at least one HE-signal (HE-SIG) field, a HE-short training field (HE-STF), and at least one HE-long training field (HE-LTF); generating a HE physical layer convergence procedure protocol data unit (HE PPDU) including the legacy preamble and the HE preamble; and transmitting, over a wireless medium, the HE PPDU, wherein the legacy preamble, the at least one HE-SIG field, and the HE-STF each have a subcarrier spacing of 312.5 kHz, and wherein the at least one HE-LTF has a subcarrier spacing of 156.25 kHz and a Discrete Fourier Transform (DFT) period having a length of 6.4 μsec when the HE PPDU is transmitted in a first communication environment, and has a subcarrier spacing of 78.125 kHz and a DFT period having a length of 12.8 μsec when the HE PPDU is transmitted in a second communication environment.