This text focuses on a specific engineering problem that is and will continue to be important in the forthcoming information age: namely, the need for highly integrated radio systems that can be embedded in wireless devices for various applications, including portable mobile multimedia wireless communications, wireless appliances, digital cellular, and digital cordless. Traditionally, the design of radio ICs involves a team of engineers trained in a wide range of fields that include networking, communication systems, radio propagation, digital/analogue circuits, RF circuits, and process technology. However, as radio ICs become more integrated, the need for a diverse skill set and knowledge becomes essential for professionals as well as students, to broaden beyond their trained area of expertise and to become proficient in related areas. The key to designing an optimized, economical solution for radio systems on a chip hinges on the designer's thorough understanding of the complex trade-offs from communication systems down to circuits. The purpose of this book is to provide a focused, top-down treatment of radio system IC design with an emphasis on digital radio systems that will play a dominant role in wireless communications in the 21st century. The intended readers of this book include both engineers as well as students whose main area of interest or line of work lies in the design and integrated circuits implementation of wireless communication ICs, with an emphasis on the integration of an entire radio system on a chip.