Introduction
Scope
This document describes the narrowband IoT (NB-IoT) radio access technology, and focuses mainly on the primary synchronization process of the NB-IoT in the downlink, which is activated when the user equipment (UE) attempts to receive data from the base station (BS) when it leaves its dormant state and wakes up.
When the UE wakes up, it must first synchronize with the time, frequency, and base station parameters (for example, cell ID or radio network temporary identifier (RNTI)) to be able to receive data. In this document, we mainly focus on the UE’s initial cell search, in which the range of the carrier frequency uncertainty is very high. This process is one of the most power-consuming processes in NB-IoT because it requires the UE to continuously activate an RX radio frequency (RF) chain and to constantly process input samples until the synchronization stage is complete…
