Internet of Things via Satellite: A Multiple-Access Performance Study of LoRa and its Enhancements

Among the proposed waveforms for the Internet of things (IoT), long range (LoRa) receives remarkable interest and has been investigated for the use in direct-to-satellite (DtS) scenarios. The large coverage area provided by low Earth orbit (LEO) satellites poses the challenging task to handle multiple-access interference. To shed the light on relevant receiver enhancements compatible with LoRa and able to support a large number of end-devices, a detailed physical layer simulator is developed. Concurrent intra-spreading factor (SF) transmissions are demodulated in parallel relying on the Pyramid technique [1], that we modified and refined. Interference cancellation as well as coherent demodulation are also incorporated in the receiver design. With extensive Monte Carlo simulations, we provide an overview of the benefits of such techniques and identify the most promising ones.