Approximate False Alarm Probability of Hchirp System Based on LoRa

LoRa has received widespread attention because they fulfill the need for long range low power communication. In this paper, we proposed a high-performance system called Hchirp based on LoRa and presented a transceiver implementation of Hchirp. In Hchirp system, the presence of false alarm may influence the performance. We proposed an approximate bound to calculate false alarm probability when receive LoRa signals for specific frame structures. In addition, the presence of carrier frequency offset (CFO) may lead to an increase in the symbol error rate (SER). Through simulation verification, we can see that Hchirp system has great SER performance under the interger CFO. For the fractional CFO, Hchirp employs the low-rate optimization (LRO) approach to enhance the robustness of signals. We verified enabling LRO can enhance system performance while reduces the data transmission rate through simulation.