Interpretation of the principles and implementation of FreeRider: A tutorial

We aims to provide an interpretation of the the design background, motivation, and key innovations of FreeRider. The technique utilized by FreeRider enables tags to transform codewords present in commodity signals into another valid ones from the same codebook during reflection. As a result, the backscattered signal remains valid as commodity radios such as ZigBee or Bluetooth. By using commodity radios, FreeRider's backscatter system addresses the issue of specialized hardware requirements, thereby expanding its potential applications across various fields such as smart homes, healthcare, and industrial environments.