公开(公告)号：US20190037549A1

公开(公告)日：2019-01-31

申请号：US15937365

申请日：2018-03-27

Applicant: Apple Inc.

Inventor： Mingguang Xu ,  Su Khiong Yong ,  Mithat C. Dogan ,  Rohit U. Nabar ,  Qi Wang ,  Kyle C. Brogle ,  Andrew J. Ringer

IPC: H04W72/04 ,  H04W64/00

Abstract: Communicating wireless devices collaborate and utilize waveforms to enable secure channel estimation. To protect against a repetitive replay attack, some embodiments include Single Carrier Physical Layer (SC-PHY) waveforms and/or interpolated OFDM waveforms that do not include a repeatable or predictable structure. The waveforms are transmitted in ranging packet structures that are compatible with legacy 802.11 technologies that do not utilize secure channel estimation. The ranging packets are received in combination with the information previously exchanged to enable the receiving wireless system to securely determine a channel estimate (e.g., determine a channel estimate without an interloper transmission that is not an authentic first arrival path in a multi-path channel between the wireless systems). Thus, one or both of the wireless systems can estimate the distance between them (or range). Devices utilizing legacy 802.11 technologies may receive the ranging packet structures and determine durations for deferring access to the channel.