Understanding of Channel State Information

Channel State Information (CSI) is one of the major types of data used in wireless sensing, thanks to its fine subcarrier-level granularity and easy access with commodity Wi-Fi devices. While it is feasible to simply process CSI as numeric data, understanding the underlying model can guide the development of more effective wireless sensing algorithms. In this chapter, we aim to introduce CSI and its main components, including various signal features and error terms. Devices supporting the CSI collection are listed at the end of this chapter.