Joint Beamforming for Integrated Satellite-Terrestrial ISAC Systems

Area of Science:

• Wireless communication networks
• Satellite systems engineering
• Signal processing

Background:

• Satellite-terrestrial integrated networks offer global coverage, crucial for remote areas.
• Integrated Sensing and Communications (ISAC) improves spectral efficiency by combining sensing and communication functions.
• Current architectures face challenges in seamless integration and resource optimization.

Purpose of the Study:

• To propose a novel integrated satellite-terrestrial ISAC architecture.
• To maximize user sum rate under various system constraints.
• To address challenges posed by both perfect and imperfect channel state information.

Main Methods:

• Formulation of a joint beamforming design problem.
• Transformation of the non-convex problem into a difference-of-convex form for perfect channel state information.
• Development of a robust method using successive convex approximation and the S-procedure for imperfect channel state information.

Main Results:

• The proposed joint beamforming design effectively maximizes the sum rate.
• The convex-concave procedure provides a solution for perfect channel state information.
• The robust method ensures performance under imperfect channel state information, outperforming benchmarks.

Conclusions:

• The novel integrated satellite-terrestrial ISAC architecture is effective.
• The proposed methods successfully address optimization challenges.
• The design is well-suited for low-Earth orbit satellite systems.