AI 中文总结
本文针对节俭式多站D-MIMO ISAC系统，提出双时间尺度正交子载波资源分配框架，以通信SE为约束最小化成像熵，实现了更优的感知-通信权衡，明确了相干与非相干成像接收机的性能优势同步机制。
AI 中文摘要
新兴的基于分布式多输入多输出（D-MIMO）的集成感知与通信（ISAC）系统，可利用多个接入点（AP）间的空间分集实现无线电成像，但感知与通信的融合会在两类信号间引入互干扰。本文提出一种下行D-MIMO ISAC框架，通过为感知和通信分配正交子载波以消除功能间干扰；该框架采用相位相干架构，其中单天线AP在为通信用户设备（UE）提供服务的同时构建环境反射率图像。我们开发了一种双时间尺度资源分配框架，以通信频谱效率（SE）为约束最小化重建图像熵，该设计遵循以通信为中心的策略，即感知使用满足通信需求后剩余的资源：长时优化（LTO）利用UE与目标随机分布的合成场景确定AP模式和子载波分配，包括通信与感知的划分以及感知子载波在发射AP间的分配；短时优化（STO）则调整通信-感知功率分配因子，以在当前场景中维持SE约束。数值结果表明，所提正交子载波分配方案与感知和通信共享相同子载波的传统叠加方案相比，可实现更优的感知-通信权衡；最后，我们评估了相干和非相干成像接收机，确定了两种方法分别能提供更优成像与定位性能的同步机制。
英文摘要
Emerging integrated sensing and communication (ISAC) systems based on distributed MIMO (D-MIMO) enable radio imaging by exploiting spatial diversity across multiple access points (APs). However, joint sensing and communication introduce mutual interference between communication and sensing signals. In this paper, we propose a downlink D-MIMO ISAC framework that allocates orthogonal subcarriers to sensing and communication to eliminate inter-function interference. We consider a phase-coherent architecture in which single-antenna APs serve communication user equipment (UEs) while constructing a reflectivity image of the environment. We develop a two-timescale resource allocation framework that minimizes reconstructed-image entropy subject to a communication spectral-efficiency (SE) constraint. The proposed design follows a communication-centric policy, where imaging uses the resources left after satisfying the communication requirement. The long-timescale optimization (LTO) determines AP modes and subcarrier assignment, including the partitioning between communication and sensing and the allocation of sensing subcarriers among transmit APs, using synthetic scenarios with random UE and target distributions. The short-timescale optimization (STO) adapts the communication-sensing power-splitting factor to preserve the SE constraint in the current scenario. Numerical results show that the proposed orthogonal subcarrier allocation achieves a superior sensing-communication trade-off compared with conventional superposition, where sensing and communication share the same subcarriers. Finally, we evaluate coherent and non-coherent imaging receivers and identify the synchronization regimes in which each approach provides better imaging and localization performance.
