A Turbo Coded LoRa-Index Modulation Scheme for IoT Communication

Long-Range (LoRa) is one of the emerging technologies in low-power wide-area networks (LPWANs). LoRa physical layer (PHY) employs chirp spread spectrum (CSS) on top of a variant of frequency shift keying (FSK), and noncoherent detection is employed at the receiver for obtaining the transmitted data symbols. In this paper, we focus on data transmission performance in Internet-of-Things (IoT) networks. This paper first analyzes the BER performance of LoRa modulation. To improve the spectral efficiency and energy efficiency, we propose a method for LoRa physical layer improvement based on index modulation and derive the theoretical error rate of the index bit and information bits. Furthermore, Turbo code is employed to improve the BER performance of the scheme. Simulation results are presented and the transmission performance is analyzed.