A communication device in a wireless local area network (WLAN) generates a first portion of a wakeup radio (WUR) packet and a second portion of the WUR packet. The first portion of the WUR packet corresponds to a WLAN legacy physical layer (PHY) preamble. Generating the second portion of the WUR packet includes: generating the second portion of the WUR packet to include a WUR packet PHY sync signal. The WUR packet PHY sync signal corresponds to a sync bit sequence with each bit in the sync bit sequence modulated by a sync waveform. The second portion of the WUR packet is generated to also include a PHY data portion and a padding signal. The padding signal corresponds to a padding bit sequence with each bit in the padding bit sequence modulated by the sync waveform. The communication device transmits the WUR packet in the WLAN.