LoRa Transceiver With Improved Characteristics

We present a novel design and implementation of a LoRa transceiver with enhanced characteristics which operates in two industrial, scientific, and medical (ISM) bands of 868 MHz and 434 MHz. Comparative tests with two widely utilized commercial transceivers were carried out to demonstrate the superior performances of the proposed transceiver, namely improved sensitivity by 15–25 dB and better immunity to interference. Field tests were performed by establishing a very long line-of-sight over land link of 112 km. The main achievements of this letter are: 1) the design of a novel high-sensitivity low-cost miniaturized LoRa transceiver; 2) demonstrating a very long LoRa link with low-cost commercial-off-the-shelf omni-directional rubber duck antennas with standard-compliant output power in the 868 MHz ISM band; and 3) temporal analysis of the link variability for different spreading factors (7, 10, 12) within a fixed LoRa bandwidth of 125 kHz.