A Novel MuLoRa Modulation Based on Fractional Fourier Transform

LoRa has been widely used in the Internet of Things (IoT). However, since LoRa only supports single symbol transmission in its bandwidth, the bit rate of LoRa is limited. This restricts the future development of LoRa, such as Smart Home, Internet of Vehicles, Satellite IoT, etc. Toward this end, based on the energy convergence characteristic of LoRa symbol in the fractional domain, we propose a multiplexed LoRa (MuLoRa) which transmits multiple LoRa symbols simultaneously in the same bandwidth. By adding address bits, the collision between multiple LoRa symbols of MuLoRa is avoided. Considering the hardware consumption of MuLoRa modulation in the time domain, a fractional domain MuLoRa modulation method based on fractional Fourier transform (FRFT) is designed. Simulation results show that MuLoRa can significantly improve the transmission bit rate than conventional LoRa under the same bandwidth. And MuLoRa can be configured more flexibly to meet the performance requirements of rate, power, collision avoidance and BER in different application scenarios in the future high data rate IoT era.