A Tutorial on NB-IoT Physical Layer Design

Abstract

The Internet of things (IoT) is transforming the whole of society. It represents the next evolution of the Internet and will significantly improve the ability to gather and analyze data, as well as the ability to control devices remotely. In this respect, the usage of connected devices is continuously growing with the expansion of the applications being offered to individuals and industries. To address IoT market needs, many low-power wide-area (LPWA) technologies have been developed, some operating on licensed frequencies (e.g., narrowband-IoT [NB-IoT] and Long-Term Evolution-M [LTE-M]), and others on unlicensed frequencies (e.g., LoRa, Sigfox, etc.). In this paper, we address the Release 13 of the NB-IoT 3rd generation partnership project (3GPP) standardized LPWA technology and provide a tutorial on its physical layer (PHY) design. Specifically, we focus on the characteristics and the scheduling of downlink and uplink physical channels at the NB-IoT base station side and the user equipment (UE) side. The goal is to help readers easily understand the NB-IoT system without having to read all the 3GPP specifications or the state-of-the-art papers that generally describe the system. To this end, each presented concept is followed by examples and concrete use-cases to further aid in the reader's comprehension. Finally, we briefly describe and highlight the new features added to the NB-IoT system in Releases 14 and 15.

The Art of Designing Remote IoT Devices—Technologies and Strategies for a Long Battery Life

“…The system is more resilient against phase noise, as phase shifts are used rather than fixed constellation points. NB-IoT is mainly a slimmed-down version of LTE and reuses the modulation techniques employed in LTE [ 31 ]. In the uplink, NB-IoT uses BPSK or Quadrature Phase Shift Keying (QPSK) depending on the coverage [ 32 ].…”

“…The system is more resilient against phase noise, as phase shifts are used rather than fixed constellation points. NB-IoT is mainly a slimmed-down version of LTE and reuses the modulation techniques employed in LTE [31].…”

An Efficient Turbo Decoding and Frequency Domain Turbo Equalization for LTE Based Narrowband Internet of Things (NB-IoT) Systems

“…Wireless IoT systems are expected to offer coverage reachability of about 164 dB, battery life of 10 years, coverage density to support up to 10 million devices in a square km 2 , and a system throughput of 200 bps with processing latencies lower than 10 s [ 13 , 14 ]. Hence, choosing a suitable PHY layer technology is essential to meet the requirement.…”

“…In addition, coverage efficiency through link adaptation, and modulation and coding scheme (MCS) index selection are considered in existing LTE technology, as well as the determination of the appropriate number of repetitions [5][6][7][8][9][10][11][12]. Wireless IoT systems are expected to offer coverage reachability of about 164 dB, battery life of 10 years, coverage density to support up to 10 million devices in a square km 2 , and a system throughput of 200 bps with processing latencies lower than 10 s [13,14]. Hence, choosing a suitable PHY layer technology is essential to meet the requirement.…”

Empirical Path Loss Channel Characterization Based on Air‐to‐Air Ground Reflection Channel Modeling for UAV‐Enabled Wireless Communications

“…The numerous deployments of Internet of Things (IoT) devices such as IoT-based WiFi IEEE 802.11 [1], LoRabased low power wide area network (LPWAN) [2], Narrowband IoT (NB-IoT) [3], or Sigfox [4] that uses in modern applications such as healthcare [5], transportation [6], smart farming [7], smart cities [8], and among others [9]. The fundamental challenges of IoT communications are channel modeling, connectivity, coverage, reliability, latency, and energy efficiency.…”