AI 中文总结
研究杂乱环境中 RIS 辅助的 ISAC 系统性能，推导通信链路容量表达式和感知的 SCNR，分离不同杂波，通过分辨率归一化指标评估距离和速度估计，蒙特卡罗仿真验证分析，揭示零多普勒杂波泄漏对 SCNR 的主导作用。
AI 中文摘要
本文分析了在存在多个散射体干扰不同类型反射感知信号的杂乱环境中，通信优化的可重构智能表面（RIS）辅助的感知与通信一体化（ISAC）系统的性能。RIS 相位在用户设备处相干组合直接和反射通信路径，但雷达回波通常未对准。对于小尺度衰落上的通信链路，推导了无 RIS 基线的精确遍历容量表达式、RIS 辅助链路的矩匹配伽马近似和詹森上界。对于感知，分析了直接距离-多普勒单元处的平均信杂噪比（SCNR），推导了各部分回波平均功率，通过范围和慢时间泄漏响应加权得到 SCNR 以分离不同杂波。使用分辨率归一化指标评估距离和速度估计。蒙特卡罗仿真结果验证了分析，表明零多普勒杂波泄漏主导 SCNR。
英文摘要
In this paper, we analyze the performance of a communication-optimized reconfigurable intelligent surface (RIS)-assisted integrated sensing and communication (ISAC) system operating in a cluttered environment where multiple scatterers may interfere with the different types of reflected sensing signals. The RIS phases coherently combine the direct and reflected communication paths at the user equipment, whereas the corresponding radar returns remain generally misaligned. In addition, static scatterers near the radar act as environmental clutter that affects only the sensing function. For the communication link over small-scale fading, we derive an exact ergodic-capacity expression for the no-RIS baseline, a moment-matched Gamma approximation for the RIS-assisted link, and a Jensen upper bound, all of which are interpreted as upper bounds on the rate of the underlying binary phase-shift keying waveform. For sensing, our analysis focuses on the average signal-to-clutter-plus-noise ratio (SCNR) at the direct range-Doppler cell. Specifically, we derive the average powers of the direct, RIS-related, and scatterer returns, which scale as constant, linear, linear, quadratic, and constant, respectively, with the number of RIS elements. We then weigh them by the range and slow-time leakage responses to obtain the SCNR, thereby separating RIS-induced clutter from geometry-governed environmental clutter. Range and velocity estimation are evaluated using resolution-normalized metrics. Our Monte Carlo simulation results validate the analysis and show that zero-Doppler clutter leakage dominates the SCNR.
