Frequency offset tolerant synchronization signal design in NB-IoT

TL;DR

This paper proposes a new synchronization signal structure for NB-IoT that effectively handles large frequency offsets, improving timing detection performance in low-cost, massive IoT deployments.

Contribution

A novel synchronization signal design using conjugated sequences to mitigate frequency offset effects in NB-IoT systems.

Findings

The proposed signal structure performs well under large frequency offsets.

Simulation results validate the effectiveness of the design in NB-IoT scenarios.

The method is suitable for low-cost, large-scale IoT applications.

Abstract

Timing detection is the first step and very important in wireless communication systems. Timing detection performance is usually affected by the frequency offset. Therefore, it is a challenge to design the synchronization signal in massive narrowband Internet of Things (NB-IoT) scenarios where the frequency offset is usually large due to the low cost requirement. In this paper, we firstly proposed a new general synchronization signal structure with a couple of sequences which are conjugated to remove the potential timing error arose from large frequency offset. Then, we analyze the suitable sequence for our proposed synchronization signal structure and discuss a special ZC sequence as an example. Finally, the simulation results demonstrate our proposed synchronization signal can work well when the frequency offset is large. It means that our proposed synchronization signal design is very suitable for the massive NB-IoT.