Indoor device-free localization and tracking can bring both convenience and privacy to users compared with traditional solutions such as camera-based surveillance and RFID tag-based tracking. Technologies such as Wi-Fi, wireless sensor, and infrared have been used to localize and track people living in care homes and office buildings. However, the presence of multiple residents introduces further challenges, such as the ambiguity in sensor measurements and target identity, to localization and tracking. In this article, we survey the latest development of device-free indoor localization and tracking in the multi-resident environment. We first present the fundamentals of device-free localization and tracking. Then, we discuss and compare the technologies used in device-free indoor localization and tracking. After discussing the steps involved in multi-resident localization and tracking including target detection, target counting, target identification, localization, and tracking, the techniques related to each step are classified and discussed in detail along with the performance metrics. Finally, we identify the research gap and point out future research directions. To the best of our knowledge, this survey is the most comprehensive work that covers a wide spectrum of the research area of device-free indoor localization and tracking.

中文翻译：

---

多居民环境下的无设备室内定位与跟踪调查

与基于摄像头的监控和基于RFID标签的跟踪等传统解决方案相比，室内免设备定位和跟踪可以为用户带来便利和隐私。Wi-Fi、无线传感器和红外线等技术已被用于定位和跟踪居住在疗养院和办公楼中的人们。然而，多个居民的存在给定位和跟踪带来了进一步的挑战，例如传感器测量和目标身份的模糊性。在本文中，我们调查了多居民环境中无设备室内定位和跟踪的最新发展。我们首先介绍无设备定位和跟踪的基础知识。然后，我们讨论和比较技术用于无设备室内定位和跟踪。在讨论了多驻地定位和跟踪所涉及的步骤（包括目标检测、目标计数、目标识别、定位和跟踪）之后，技术与每个步骤相关的内容与性能指标一起被分类和详细讨论。最后，我们确定了研究差距并指出了未来的研究方向。据我们所知，这项调查是最全面的工作，涵盖了无设备室内定位和跟踪的广泛研究领域。