Green Software De?ned Radios, the title of this book may have originated from a lackofinspiration, andthecombinationofhardwork, jetlag, anddrinkinggreentea. The message we want to convey however, is that SDRs are a promising technology for the future, providing they are designed for ef?cient usage of scarce resources: energy and spectrum. In the last years, the R&D teams focusing on wireless c- munication (around the world and at IMEC speci?cally), have realized great bre- throughs. It is our honor, building on this knowledge, to bring a comprehensive overview of the essential technologies....