Patent ID: 9667462
Date: 2017-05-30
CPC Classifications: H04L,H04W

Claim:
1. A method comprising: receiving, at a communication device, a physical layer (PHY) data unit having a preamble, wherein the preamble includes (i) a first preamble portion, and (ii) a second preamble portion following the first preamble portion; determining, at the communication device, whether a modulation of a first orthogonal frequency division multiplexing (OFDM) symbol in the first preamble portion is rotated with respect to an expected modulation of the first OFDM symbol of a first PHY format defined by a communication protocol; when it is determined that the modulation of the first OFDM symbol is not rotated with respect to the expected modulation of the first OFDM symbol of the first PHY format, determining, at the communication device, that the preamble of the PHY data unit conforms to the first PHY format; when it is determined that the preamble of the PHY data unit conforms to the first PHY format, processing, at the communication device, the second preamble portion of the PHY data unit according to the first PHY format; and when it is determined that the modulation of the first OFDM symbol is rotated with respect to the expected modulation of the first OFDM symbol of the first PHY format,