Timestamping and Ranging Performance for IEEE 802.15.4 CSS Systems

This paper deals with the characterization of IEEE 802.15.4 using the chirp spread spectrum (CSS) physical layer. A new test bench, which has full bandwidth capability and extreme flexibility because of the field programmable gate array-based probes, is used for managing reproducible measurement results. Several scenarios and algorithms have been considered for the estimation of the IEEE 802.15.4 CSS performance in real indoor environments. The absolute timestamping errors have been evaluated using the distributed synchronization feature (synchronous Ethernet) of the test bench probes. The ranging performance has been evaluated using both two-way ranging (TWR) and symmetrical double-sided TWR approaches. The characterization results in indoor situations show that the tested implementation of IEEE 802.15.4 CSS achieves mean timestamping errors of 200 ps, and a ranging root mean square error down to 0.5 m. Moreover, the CSS modulation highlights a good robustness against interference.