LR-FHSS Networks With Orthogonal Physical Channels for Headers and Payload Fragments

This letter introduces an enhancement to the long-range frequency-hopping spread spectrum (LR-FHSS), a modulation within the LoRaWAN specification, particularly useful in dense networks supported by satellite gateways. LR-FHSS replicates headers and payload fragments across different physical channels, but the distinct transmission strategies for headers and payloads can lead to uneven success rates and degrading performance. To address this, we propose a scheme that allocates orthogonal physical channels for headers and payloads. Through analytical and simulation results, considering factors, such as payload size and the number of users, we identify the optimal distribution of channels between headers and payloads to maximize success probability. The proposed scheme significantly improves performance, supporting up to 50% more users at the same reliability level as the standard LR-FHSS.