Time transfer in impulse radio networks

The synchronization of clocks at physically separated network nodes requires timed signal exchanges between the nodes. Ultra-wideband (UWB) impulse signals potentially provide the means for doing this very accurately, but unlike narrowband signals, pulse signals are more naturally suited to time-division multiple-access (TDMA) schemes. In this work, we describe TDMA time-transfer schemes that estimate the mappings from a master node´s clock time into slaves´ clock times based on specific wireless measurements. We propose an optimal approach to distribution of UWB transmissions between those that perform alignment of nodes´ clock rates and those that determine clock offsets. Analytical equations for the timing error variances are derived and our results suggest a possible lower bound for time-transfer error using UWB impulse signals.