Noncoherent Maximum Likelihood Detection for LoRa Signals in Multipath Fading
arXiv:2604.13778
The paper derives a noncoherent maximum‑likelihood detector for LoRa signals that relies only on channel statistics (no instantaneous CSI), and demonstrates that it improves detection performance over Rician multipath fading channels, matching or surpassing coherent schemes especially when Doppler shift is present.
Abstract
This letter derives the noncoherent (NC) maximum likelihood (ML) detection rule for LoRa signals under Rician multipath fading channels. The proposed NC-ML detection only requires the channel statistics, not the actual instantaneous channel state information (CSI), which eliminates the overhead associated with channel estimation. Simulation results show that despite the low-complexity, the proposed detection scheme significantly improves the performance of LoRa detection over multipath channels. Notably, in time-invariant channels, the NC-ML receiver can achieve equivalent performance as compared to existing coherent schemes, and even surpasses them when Doppler shift is present, while not relying on the channel estimation nor reference signals extracted from the preamble.
5 pages, 3 figures