Abstract: In order to improve the transmission rate of LoRa technology, a new demodulation algorithm for LoRa synchronous superimposed signals is proposed. In this paper, we first theoretically find that the core problem of demodulation of LoRa superposition signals in the same expansion frequency channel is to distinguish the signals of different nodes, and if the power difference of two nodes is greater than 5 dB, the data of the two nodes can be demodulated. Moreover, the disadvantages of the method are also indicated. Second, we propose a algorithm of using the LoRa modulation symbol as the highest marker bit to distinguish the data of two nodes, indicate the application scenario of the algorithm, and prove that it has the same complexity as the demodulation algorithm of LoRa technique. Simulation results show that the new algorithm will not increase the bit error rate of the LoRa demodulation algorithm, and compared with the demodulation algorithm of LoRa technology, the new algorithm greatly improves the transmission rate of LoRa packets and reduces the bit energy consumption of transmitting effective information.

Key words: LoRa, superposed signal, flag bit, transmission rate, bit energy consumption