DESIGN AND IMPLEMENTATION OF LORA COMMUNICATION SYSTEM BASED ON SOFTWARE DEFINED RADIO FOR DIRECT-TO-SATELLITE INTERNET OF THINGS (DTS-IOT) APPLICATIONS ON EQUATORIAL LEO SATELLITE CONSTELLATIONS

• Main Author: Eighfansyah Susilo, Hogan
• Format: Theses
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/84268
• Institution: Institut Teknologi Bandung

The rapid growth of the Internet of Things (IoT) demands reliable and cost-effective communication solutions, particularly in remote areas. Low Earth Orbit (LEO) Satellite and Software Defined Radio (SDR) technology offer significant potential in supporting Direct-to-Satellite IoT (DtS-IoT) communications. This research develops an IoT communication system based on LoRa using SDR for DtS-IoT applications on LEO satellites. The results demonstrate that the SDR-based IoT LoRa Gateway can support reliable LoRa communication. Testing showed optimal performance with LoRa parameters SF7 with a bandwidth (BW) of 125 kHz, SF10 with BW 250 kHz, and SF12 with BW 500 kHz at a frequency of 923 MHz, achieving a Packet Delivery Ratio (PDR) greater than 98% for 50-byte data packets. In multi-user applications, the gateway can receive and decrypt data from users with different LoRa parameters. The SDR- based IoT Ground Terminal design was also successfully implemented, supporting optimal LoRa modulation. The best performance was achieved at SF12 and BW 250 kHz, with a maximum transmission power of 6.94 dBm without a High Power Amplifier (HPA) and 27.12 dBm with HPA, demonstrating high flexibility in multi- user scenarios. The SDR-based LEO satellite communication channel simulator developed in this research accurately replicates satellite channel conditions. It recorded low error rates for Total Loss, with 2 dB at frequencies of 923 MHz and 2200 MHz. For Doppler effects, errors were 201 Hz (< 3%) for 923 MHz and 480 Hz (< 3%) for 2200 MHz. Latency errors were insignificant. This simulator is effective in analyzing LoRa communication performance and can also emulate LEO satellite communication channels at low or near-equatorial inclinations, particularly in cases of low-inclination satellites.