Approximate BER Performance of LoRa Modulation With Heavy Multipath Interference

This letter proposes a method to approximate LoRa performance over heavy multipath channels. Firstly, the multipath time delay and LoRa signal duration are combined to analyze the path overlapping interference quantitatively. Then simple BER approximations in coherent and non-coherent detections are derived with Gaussian Q-function and algebraic formulas. With the heavy multipath channel model in 3GPP to mimic the realistic indoor industrial scenarios, the approximate expressions are verified by Monte Carlo simulations. Moreover, performance comparison results show that a high spreading factor leads to severe multipath overlap and may result in BER reduction.

Automated summary

This letter proposes a method to estimate the performance of LoRa in heavy multipath channels using approximations. By analyzing the interference caused by path overlapping quantitatively, the authors derive simple approximations for bit error rate in both coherent and non-coherent detections. They verify their expressions through Monte Carlo simulations with a realistic indoor industrial scenario model. Performance comparison results demonstrate that a high spreading factor can lead to severe multipath overlap and reduce the bit error rate.