Through-wall human sensing is of high interest for both military and nonmilitary applications, including counter-terrorism and law enforcement purposes, particularly in the modern, highly urbanized environment. Conventional active radar sensors possess good performance, however, at the expense of high cost and complexity of the transmitter/receiver design. This article demonstrates the effectiveness of a passive through-wall human sensing technique using opportunistic WiFi signals. With a simple software-defined radio receiver and advanced signal processing techniques, the position of indoor WiFi access point can be accurately localized, and its signal can be exploited to clearly detect the Doppler/micro-Doppler of human motions inside the room. Compared to the results in the current literature, this article demonstrates better detection sensitivity and capability to sense not only major motions such as walking and waving hand, but also very small human motions such as keyboard typing and breathing. In addition, an iterative adaptive approach is applied to effectively improve the Doppler resolution of WiFi passive radar. These enhanced sensitivities greatly expand the potential of WiFi passive radar for through-wall sensing applications.

中文翻译：

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使用 WiFi 无源雷达进行穿墙人体感应


穿墙人体感应对于军事和非军事应用都具有很高的兴趣，包括反恐和执法目的，特别是在现代高度城市化的环境中。然而，传统的有源雷达传感器具有良好的性能，但代价是发射器/接收器设计的高成本和复杂性。本文展示了使用机会 WiFi 信号的被动穿墙人体感应技术的有效性。通过简单的软件定义无线电接收器和先进的信号处理技术，可以准确定位室内WiFi接入点的位置，并利用其信号清晰地检测房间内人体运动的多普勒/微多普勒。与现有文献的结果相比，本文展示了更好的检测灵敏度和能力，不仅可以感知行走和挥手等主要动作，还可以感知键盘打字和呼吸等非常小的人体动作。此外，采用迭代自适应方法有效提高WiFi无源雷达的多普勒分辨率。这些增强的灵敏度极大地扩展了 WiFi 无源雷达在穿墙传感应用中的潜力。