This paper explores a novel research direction where a digital twin is leveraged to assist the beamforming design for an integrated sensing and communication (ISAC) system. In this setup, a base station designs joint communication and sensing beamforming to serve the communication user and detect the sensing target concurrently. Utilizing the electromagnetic (EM) 3D model of the environment and ray tracing, the digital twin can provide various information, e.g., propagation path parameters and wireless channels, to aid communication and sensing systems. More specifically, our digital twin-based beamforming design first leverages the environment EM 3D model and ray tracing to (i) predict the directions of the line-of-sight (LoS) and non-line-of-sight (NLoS) sensing channel paths and (ii) identify the dominant one among these sensing channel paths. Then, to optimize the joint sensing and communication beam, we maximize the sensing signal-to-noise ratio (SNR) on the dominant sensing channel component while satisfying a minimum communication signal-to-interference-plus-noise ratio (SINR) requirement. Simulation results show that the proposed digital twin-assisted beamforming design achieves near-optimal target sensing SNR in both LoS and NLoS dominant areas, while ensuring the required SINR for the communication user. This highlights the potential of leveraging digital twins to assist ISAC systems.

翻译：本文探索了一个新颖的研究方向，即利用数字孪生辅助集成感知与通信（ISAC）系统的波束成形设计。在该设置中，基站设计联合通信与感知波束成形，以同时服务通信用户并检测感知目标。利用环境的电磁（EM）三维模型和射线追踪技术，数字孪生可以提供多种信息（例如传播路径参数和无线信道）以辅助通信和感知系统。具体而言，我们基于数字孪生的波束成形设计首先利用环境电磁三维模型和射线追踪来（i）预测视距（LoS）与非视距（NLoS）感知信道路径的方向，并（ii）从这些感知信道路径中识别出主导路径。随后，为优化联合感知与通信波束，我们在满足最小通信信号与干扰加噪声比（SINR）要求的同时，最大化主导感知信道分量上的感知信噪比（SNR）。仿真结果表明，所提出的数字孪生辅助波束成形设计在LoS和NLoS主导区域均能实现接近最优的目标感知SNR，同时确保通信用户所需的SINR。这凸显了利用数字孪生辅助ISAC系统的潜力。