| 摘要: |
| 为了研究近海场景下通信感知一体化（Integrated Sensing and Communication，ISAC）系统的联合资源分配问题，构建了包含岸边基站、多天线中继船与多用户船的三层网络模型，并进一步建立物理系统与虚拟模型相结合的数字孪生驱动优化框架。通过对物理近海ISAC系统的实时状态进行映射，在虚拟空间中完成资源优化决策，并将优化结果反馈至物理网络执行，实现虚实协同的闭环优化机制。为刻画海面传播特性，采用三射线信道模型，综合考虑直射径、海面反射径及波导折射径的影响。以系统总发射功率最小化为目标，在满足用户最低速率约束、感知信噪比约束以及基站与中继发射功率上限的条件下，联合优化子载波分配与波束赋形矩阵。针对该非凸问题，采用半正定松弛与变量替换方法，将波束赋形向量转化为协方差矩阵形式，并结合惩罚函数与连续凸近似（Successive Convex Approximation，SCA）方法，将原问题转化为一系列可求解的凸优化子问题，进而使用CVX工具箱进行迭代求解。仿真结果表明，所提算法可在约6次迭代内稳定收敛，在满足通信与感知性能约束的条件下，与现有工作相比可有效降低近海系统的功耗。同时，与仅依赖岸边基站直达链路的系统相比，所提出的中继辅助ISAC架构可降低高达50%的系统功耗。 |
| 关键词: 近海通信 通信感知一体化（ISAC） 资源分配 波束赋形 数字孪生 |
| DOI：10.20079/j.issn.1001-893x.260115002 |
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| 基金项目: |
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| Digital Twin-driven Joint Resource Optimization Strategy for Nearshore ISAC Systems |
| LI Xuehua,DING Yuxin,CAI Yuanxin,GONG Yi |
| (School of Information Communication Engineering，Beijing Information Science and Technology University，Beijing 102206，China) |
| Abstract: |
| To investigate the joint resource allocation problem in nearshore integrated sensing and communication(ISAC) systems，a three-layer network model is established，consisting of shore-based base stations，multi-antenna relay vessels，and multiple user vessels.Furthermore，a digital twin-driven optimization framework integrating the physical system with its virtual counterpart is established.By mapping the real-time states of the physical nearshore ISAC system into the virtual space，resource optimization decisions are performed within the digital domain and subsequently fed back to the physical network for execution，thereby enabling a closed-loop virtual-physical collaborative optimization mechanism.To characterize sea-surface propagation，a three-ray channel model is adopted，incorporating the direct path，sea-surface reflected path，and waveguide refracted path.With the objective of minimizing the total system transmission power，the subcarrier allocation and beamforming matrices are jointly optimized，subject to constraints on minimum user rate，sensing signal-to-noise ratio(SNR)，and maximum transmit power of base stations and relays.To address this non-convex problem，semi-definite relaxation and variable substitution technique are applied to transform the beamforming vectors into covariance matrices.Combined with a penalty function and the Successive Convex Approximation(SCA) method，the original problem is transformed into a sequence of tractable convex subproblems，which are then solved iteratively using the CVX toolbox.Simulation results show that the proposed algorithm can stably converge within approximate six iterations.Under the communication and sensing performance constraints，the proposed method effectively reduces the power consumption of the nearshore system compared with existing approaches.Furthermore，compared with systems relying solely on the direct link from the coastal base station，the proposed relay-assisted ISAC architecture can achieve up to a 50% reduction in system power consumption. |
| Key words: nearshore communication integrated sensing and communication（ISAC） resource allocation beamforming digital twin |
《电讯技术》编辑部 