Critical Design of Signal Generator Subsystem for GK-3 SBAS Payload

Inone Joo*, Cheonsig Sin

The GEO KOMPSAT-3 (GK-3) satellite, scheduled for launch in 2027, is designed to deliver public satellite communication services. It features a broadband communication payload, a satellite- based augmentation system (SBAS) payload, and a data collection payload. The GK-3 SBAS payload is set to replace the MEASAT-3D mission, which is currently leased from a Malaysian telecommunications company for the Korea Augmentation Satellite System (KASS), upon its mission's conclusion. Additionally, the GK-3 SBAS payload will support the development and verification of algorithms to improve the Korean SBAS service. To support this, a ground verification system (GVS) is being developed to assess the functionality and performance of the GK-3 SBAS payload. This system includes a Radio Frequency Generation subsystem (RF system) and a Signal Generator subsystem (SGS). This paper focuses on the critical design aspects of the SGS subsystem. The SGS has two primary functions: generating SBAS messages and L1/L5 signals in accordance with SBAS L1/L5 standards, and managing synchronization between codes and carriers to align SBAS L1/L5 GPS-like signals with GPS time. The paper presents the critical design of the SGS, including its components and equipment.

Keywords: GK-3, SBAS, SGS, design