The book addresses the challenges in chipless RFID reader architecture and to provide signal processing solutions that will lead to high-performing chipless RFID readers. After an introductory chapter, the book is divided into two sections, discussing the two main challenges of chipless RFID systems, namely detection and multiple access/localization. In the first section, the authors discuss new approaches to chipless RFID detection, such as the use of mathematical models based on signal space representation and the singularity expansion method (SEM) for data extraction. The second section introduces collision and error correction protocols, as well as time-frequency analysis and FMCW radar techniques to improve multi-tag identification.