Effective Chirp Modulation Communication System Design for LEO Satellite IoT

The high-dynamic Doppler frequency offset presents great challenges to communications in the low-Earth orbit (LEO) satellite Internet of Things (IoT) scenarios, including the high-complexity receiver synchronization algorithm, frequency tracking capability, and high-receiver sensitivity. In this article, we propose an effective communication system architecture based on chirp modulation for LEO satellite IoT with reference to LoRa system. Our approach introduces an improved chirp modulation based on low-rate optimization (LRO) with specified frequency interval and a CRC-assisted decoding scheme. Simulation results show that the proposed optimal LRO factor can improve the spectral efficiency. Furthermore, we propose a low-complexity synchronization algorithm and LRO-based frequency tracking strategy. The simulation results confirm the feasibility of the proposed communication system for LEO satellite IoT, which demonstrates robust performance under high-dynamic Doppler frequency offsets.