Integrated Sensing, Communication, and Computation in SAGIN: Joint Beamforming and Resource Allocation

The Space-Air-Ground Integrated Network utilizes integrated sensing, communication, and computation (ISCC) technology to address 6G users’ demands, but as the ISCC services expand, resource allocation and interference management become new challenges. To address these questions, a NOMA-MIMO-based space-air-ground ISCC system is proposed which include unmanned aerial vehicles (UAVs) integrated sensing, communication, and computation functions. Communication and sensing between the ground layer and UAVs are achieved through NOMA-MIMO technology, maximizing computation offloading capacity and suppressing interference between communication and sensing. Low Earth orbit satellite in the space layer can communicate with UAVs, providing ample computational resources for task processing. To minimize the system’s weighted energy consumption, a joint non-convex optimization problem is formulated and decomposed into sub-problems: beamforming design, offloading ratio optimization, and computation resource allocation optimization. An algorithm is proposed to solve these sub-problems using fractional programming based on quadratic transformation, weighted minimum mean square error, and successive convex approximation methods. Simulation results show that: i) The proposed system and algorithms significantly reduce system energy consumption compared to the benchmark scheme while ensuring sensing, communication, and computation performance, and ii) NOMA-MIMO can achieve effective interference management and improve resource efficiency.