Perception of human beings has evolved from natural biosensor to
powerful sensors and sensor networks. In sensor networks, trillions of
devices are interconnected and sense a broad spectrum of contexts for
human beings, laying the foundation of Internet of Things (IoT).
However, sensor technologies have several limitations relating to
deployment cost and usability, which render them unacceptable for
practical use. Consequently, the pursuit of convenience in human
perception necessitates a wireless, sensorless and contactless sensing
paradigm.
Recent decades have witnessed rapid developments in wireless sensing
technologies, in which sensors detect wireless signals (such as
acoustic, light, and radio frequency) originally designed for data
transmission or lighting. By analyzing the signal measurements on the
receiver end, channel characteristics can be obtained to convey the
sensing results. Currently, significant effort is being devoted to
employing the ambient Wi-Fi, RFID, Bluetooth, ZigBee, and television
signals for smart wireless sensing, eliminating the need for dedicated
sensors and promoting the prospect of the Artificial Intelligence of
Things (AIoT).
This book provides a comprehensive and in-depth discussion of wireless
sensing technologies. Specifically, with a particular focus on
Wi-Fi-based sensing for understanding human behavior, it adopts a
top-down approach to introduce three key topics: human detection,
localization, and activity recognition. Presenting the latest advances
in smart wireless sensing based on an extensive review of
state-of-the-art research, it promotes the further development of this
area and also contributes to interdisciplinary research.
