Human Presence Detection (HPD) is key to enable intelligent power management and security features in everyday devices. In this paper we propose the first HPD solution that leverages monostatic Wi-Fi sensing and detects user position using only the built-in Wi-Fi hardware of a device, with no need for external devices, access points, or additional sensors. In contrast, existing HPD solutions for laptops require external dedicated sensors which add cost and complexity, or rely on camera-based approaches that introduce significant privacy concerns. We herewith introduce the Range-Filtered Doppler Spectrum (RF-DS), a novel Wi-Fi sensing technique for presence estimation that enables both range-selective and temporally windowed detection of user presence. By applying targeted range-area filtering in the Channel Impulse Response (CIR) domain before Doppler analysis, our method focuses processing on task-relevant spatial zones, significantly reducing computational complexity. In addition, the use of temporal windows in the spectrum domain provides greater estimator stability compared to conventional 2D Range-Doppler detectors. Furthermore, we propose an adaptive multi-rate processing framework that dynamically adjusts Channel State Information (CSI) sampling rates-operating at low frame rates (10Hz) during idle periods and high rates (100Hz) only when motion is detected. To our knowledge, this is the first low-complexity solution for occupancy detection using monostatic Wi-Fi sensing on a built-in Wi-Fi network interface controller (NIC) of a commercial off-the-shelf laptop that requires no external network infrastructure or specialized sensors. Our solution can scale across different environments and devices without calibration or retraining.

翻译：人体存在检测（HPD）是实现日常设备智能电源管理与安全功能的关键。本文提出了首个利用单站Wi-Fi感知的HPD解决方案，该方案仅需设备内置Wi-Fi硬件即可检测用户位置，无需外部设备、接入点或额外传感器。相比之下，现有笔记本电脑的HPD方案需依赖增加成本与复杂性的外部专用传感器，或采用引发严重隐私顾虑的基于摄像头的方法。本文提出距离滤波多普勒频谱（RF-DS）——一种用于存在估计的新型Wi-Fi感知技术，可实现用户存在的距离选择性及时间窗检测。通过在多普勒分析前对信道脉冲响应（CIR）域实施定向距离区域滤波，我们的方法将处理聚焦于任务相关空间区域，显著降低了计算复杂度。此外，与传统的二维距离-多普勒检测器相比，在频谱域采用时间窗能提供更高的估计器稳定性。进一步地，我们提出一种自适应多速率处理框架，可动态调整信道状态信息（CSI）采样率——在空闲时段以低帧率（10Hz）运行，仅在检测到运动时切换至高帧率（100Hz）。据我们所知，这是首个利用商用现货笔记本电脑内置Wi-Fi网络接口控制器（NIC）进行单站Wi-Fi感知的低复杂度占位检测方案，且无需外部网络基础设施或专用传感器。我们的解决方案无需校准或重新训练即可适配不同环境与设备。