In this work, we study integrated sensing and communication (ISAC) networks with the aim of effectively balancing sensing and communication (S&C) performance at the network level. Focusing on monostatic sensing, the tool of stochastic geometry is exploited to capture the S&C performance, which facilitates us to illuminate key cooperative dependencies in the ISAC network and optimize key network-level parameters. Based on the derived tractable expression of area spectral efficiency (ASE), we formulate the optimization problem to maximize the network performance from the view point of two joint S&C metrics. Towards this end, we further jointly optimize the cooperative BS cluster sizes for S&C and the serving/probing numbers of users/targets to achieve a flexible tradeoff between S&C at the network level. It is verified that interference nulling can effectively improve the average data rate and radar information rate. Surprisingly, the optimal communication tradeoff for the case of the ASE maximization tends to employ all spacial resources towards multiplexing and diversity gain, without interference nulling. By contrast, for the sensing objectives, resource allocation tends to eliminate certain interference especially when the antenna resources are sufficient, because the inter-cell interference becomes a more dominant factor affecting sensing performance. Furthermore, we prove that the ratio of the optimal number of users and the number of transmit antennas is a constant value when the communication performance is optimal. Simulation results demonstrate that the proposed cooperative ISAC scheme achieves a substantial gain in S&C performance at the network level.

翻译：本文研究通感一体化网络，旨在网络层面有效平衡感知与通信性能。聚焦于单站感知，我们利用随机几何工具刻画通感性能，从而揭示通感一体化网络中的关键协同依赖关系并优化网络级核心参数。基于推导出的区域频谱效率可处理表达式，我们从两种通感联合度量视角出发，构建了网络性能最大化优化问题。为此，我们进一步联合优化了面向感知与通信的协同基站簇规模以及用户/目标的调度/探测数量，以实现网络层面通感性能的灵活权衡。验证表明，干扰消除能有效提升平均数据速率与雷达信息率。有趣的是，在区域频谱效率最大化情形下，最优通信权衡倾向于将所有空间资源用于复用与分集增益，而无需进行干扰消除。相比之下，对于感知目标，资源分配更倾向于消除特定干扰，尤其在天线资源充足时，因为小区间干扰成为影响感知性能的主导因素。此外，我们证明当通信性能最优时，最优用户数与发射天线数的比值为常数。仿真结果表明，所提出的协同通感一体化方案在网络层面实现了通感性能的显著提升。