Abstract:
In 5G radio access network, emerging machine type communications in industrial automation, smart grids, automotive and other critical applications
has increased the importance of accurate distribution of time synchronization reference up to the device/UE level. For instance, executing real-time
isochronous operations in collaborating robots, monitoring, and fault localization in smart grids requires ultra-tight synchronization among the devices.
To achieve such level of synchronism at the devices, an over-the-air time synchronization procedure must accurately estimate the base station (BS) to UE
propagation delays. In this thesis, we use timing advance (TA) mechanism
as an estimator for time of arrival (ToA) for adjusting the effect of propagation delay in synchronization procedure. We study the impact of TA binning
on propagation delay estimation, and importantly analyze how multipath
channels (a true characteristic of Industrial Internet-of-thing (IoT) environments) deteriorates the estimation. Our analysis shows that multipath channels could introduce large errors in synchronization while, averaging multiple
consecutive TA values, in static device deployments, brings the errors to an
acceptable level, i.e., less than 1 µs, assuming that the BS-UE clock disparity
has already been mitigated.
