TY  - JOUR
T1  - Opportunistic Uplink NORA for LEO Satellite-Based IoT Networks
AU  - Han, Young Jin 
AU  - Lee, Ki-Hun 
AU  - Jung, Bang Chul 
JO  - The Journal of Korean Institute of Communications and Information Sciences
PY  - 2025
DA  - 2025/1/1
DO  - 10.7840/kics.2025.50.9.1405
KW  - low-earth orbit (LEO) satellite
KW  - IoT
KW  - network
KW  - non-orthogonal random
KW  - access (NORA)
KW  - opportunistic
KW  - transmission
AB  - In this paper, we propose an opportunistic non-orthogonal random access (O-NORA) system for low-earth orbit (LEO) satellite-based uplink internet- of-things (IoT) networks. Each IoT device on the ground transmits a packet only when its channel gain exceeds a predefined threshold, which is determined by the transmission probability. The LEO satellite then decodes the transmitted signals using simultaneous non-unique decoding (SND) method.
Simulation results show that the proposed O-NORA system significantly outperforms existing non-orthogonal random access (NORA) systems based on fully random transmission.