An Unbalanced QPSK-Based Integrated Communication-Ranging System for Distributed Spacecraft Networking.

Area of Science:

• Spacecraft systems engineering
• Satellite communication technology
• Navigation and ranging systems

Background:

• Spacecraft tracking, telemetering, and command (TT&C) systems are crucial for celestial and terrestrial networks.
• Relative ranging and high-data-rate communication are essential for satellite formation flying and distributed spacecraft networks.
• Existing systems face challenges in achieving both precise ranging and efficient communication simultaneously.

Purpose of the Study:

• To introduce an integrated communication-ranging system (ICRS) for Master/Slave satellite architectures.
• To enable precise ranging and high-data-rate communication within a single system.
• To optimize power resource allocation for improved system performance.

Main Methods:

• Developed an ICRS based on inter-satellite spread spectrum ranging and UQPSK-modulated communication.
• Utilized in-phase (I) branches for ranging (with GNSS-like signals) and quadrature (Q) branches for communication (with BPSK modulation).
• Investigated the power resource allocation using a power distribution factor (PWDF) and analyzed the influence of clock offset.

Main Results:

• The proposed ICRS demonstrated excellent performance in reducing ranging error.
• The system achieved a low bit error rate (BER), indicating reliable communication.
• A reasonable power distribution factor (PWDF) was identified for optimal performance.

Conclusions:

• The integrated communication-ranging system (ICRS) effectively meets the demands for precise ranging and high-data-rate communication in advanced satellite networks.
• The proposed modulation and branch allocation strategy are effective for dual-functionality.
• Further analysis confirmed the system's robustness against clock offset, with a recommended PWDF for practical application.