A wireless device may include processing circuitry that is configured to process a first portion of a packet, the first portion of the packet comprising a legacy signal (L-SIG) field, and determine whether a constellation of a field of a second portion of the packet is binary phase shift keying (BPSK) or quaternary binary phase shift keying (QBPSK). The processing circuitry may be further configured to: process the second portion of the packet in accordance with a packet structure indicated by the constellation.