低功耗广域网LoRa技术进展与研究挑战

Progress and Challenges of LoRa Low Power Wide Area Networks

物联网的快速发展催生了大量新型的应用模式和互联生态,推动了产业数字化和智能化发展.物联网通过连接传感器、可穿戴设备、智能表计等低数据率、低功耗终端,赋予大量普通设备计算和联网的能力.随着应用场景和系统规模的扩展,传统无线技术难以适应物联网大规模、低功耗、远距离的设备组网要求.如何降低设备接入门槛、实现设备低功耗远距离连接,是当前物联网面临的重要挑战.LoRa(Long Range)作为一种代表性的低功耗广域网技术,有效解决了低功耗设备远距离连接问题,已成为物联网的核心支撑技术.然而LoRa在规模化应用中仍面临以下三方面重要挑战:(1)大规模连接场景高并发传输导致信号冲突,设备并发接入困难;(2)远距离无线链路信号衰减剧烈,弱信号可靠传输困难;(3)物联网共享信道异构协议干扰问题突出,广域异构共存困难.本文概述了现阶段低功耗广域物联网技术研究进展,重点阐述现有技术在实际应用场景中面临的三方面研究挑战及对应的技术方案.针对高并发冲突问题,现有研究提出冲突避免和并发解码方法;针对弱信号问题,现有研究在弱信号增强传输和接收端解码优化两个方面展开探索;针对异构协议竞争问题,现有研究设计了多种设计跨协议通信机制.本文综述了LoRa低功耗广域网最新相关研究,分析现有工作的创新点和局限性,并指出了低功耗广域网未来研究和发展的方向.

The rapid development of the internet of things(IoT)has spawned a large number of new applications.IoT empowers ordinary devices with computing and networking capabilities by connecting sensors,wearable devices,smart meters,and other low-data-rate,low-power end devices.Traditional wireless technologies struggle to adapt to the large-scale,low-power,long-distance connectivity requirements of IoT.How to reduce the barrier to device access and achieve lowpower,long-distance device connectivity is an important challenge facing current IoT systems.LoRa,as a representative low-power wide-area network(LPWAN)technology,effectively solves the problem of long-distance connectivity for lowpower devices and has become the core supporting technology of the IoT.However,LoRa still faces three important challenges in practice:(1)high-concurrency transmission in large-scale connection scenarios leads to signal conflicts,making it difficult for devices to access concurrently;(2)signal attenuation in long-distance wireless links makes it difficult to reliably transmit weak signals;(3)the problem of interference from heterogeneous protocols in IoT shared channels is prominent,and heterogeneous coexistence is difficult.This article outlines the current research progress of LoRa,focusing on the three research challenges and corresponding technological progress.Existing research has proposed conflict avoidance and concurrent decoding methods to address the problem of high-concurrency conflicts;existing research explores weak signal enhancement transmission and receiver decoding optimization to address the problem of weak signals;existing research has designed various cross-protocol communication mechanisms to address the problem of heterogeneous protocol competition.This article reviews the latest research progress of LoRa,analyzes the innovation points and limitations of existing research,and points out the direction of future research.