An LR-FHSS Receiver for a Massive IoT Connectivity

Long Range-Frequency Hopping Spread Spectrum (LR-FHSS) is an extension of the LoRa physical (PHY) layer that has been recently announced by Semtech and will be supported on their chips. This new PHY layer is designed to address extremely long-range and large-scale communication scenarios, such as satellite Internet of Things (IoT). LR-FHSS features high interference resistance that alleviates packet collisions by increasing the spectral efficiency with an uplink modulation based on the frequency hopping spread spectrum (FHSS). Subsequently, each data packet being sent from an LR-FHSS device is split into small pieces, which are randomly spread over a defined frequency bandwidth. In this paper, we propose several interference blanking techniques allowing increasing the number of simultaneously received LR-FHSS signals, that are accurately decoded, over the same hopping bandwidth. This processing would increase the capacity of LR-FHSS receivers and make this technology more suited to be deployed in satellite IoT applications, which entails the connectivity of a massive number of devices.