Radios, once implemented purely in hardware, are increasingly built using programmable digital signal processing (DSP) devices that enhance device flexibility, simplify manufacture, and reduce costs. This is the first comprehensive educational resource for students who want to learn the latest techniques for building software radios for wireless systems and devices. It introduces the key concepts of software radio design, and covers every issue and technique engineers must understand to successfully utilize DSP in their radio systems, including key interactions amongst analog and digital subsystems. Coverage includes: the central role of multirate DSP in software radio design; advanced digital processing techniques for constructing RF front-ends; direct digital synthesis of modulated waveforms; A/D and D/A converters and conversion processes; and smart antennas and adaptive array algorithms. The author also offers practical guidance for choosing among DSP microprocessors, FPGAs, and ASICs; as well as a systematic, object-oriented approach to programming software-based radios.