Improving Range Accuracy of IEEE 802.15.4a Radios In the Presence of Clock Frequency Offsets

Two-way time-of-arrival (TW-ToA) is a ranging protocol that provides distance between two devices in absence of synchronization, but it suffers from range estimation errors when clock frequency offset is present. In this work, we provide a timing counter management scheme for TW-ToA that suppresses ranging errors induced by any clock frequency offset between a transmitter and receiver pair. The suggested scheme is shown to be superior both theoretically and empirically to the one that is recommended in the IEEE 802.15.4a standard.