Learn the language of wireless devices and build your own digital communications systems with software-defined radio. From Wi-Fi routers to garage door openers, our lives revolve around wireless digital communication. Hacking Digital Radios demystifies these communications using the revolutionary technology of software-defined radio (SDR). With little more than a laptop, an antenna, and some SDR hardware, readers will learn how to build digital communications systems and investigate the signals all around them. With a learn-by-doing approach that emphasizes hands-on experimentation over abstract theory or complex math, Hacking Digital Radios guides readers through transmitting and receiving digital data. You'll then build on that foundation, learning to detect, capture, identify, and reverse-engineer digital radio signals. Using the intuitive, open source GNU Radio software, you'll learn to: Send and receive data using OOK and FSK, the two most common modulation schemes for digital data Encode text, images, and other types of data in radio signals Use clock synchronization to extract binary data from received transmissions Identify preambles, sync words, payload data, and other components of digital signals Implement checksums and other measures to ensure data integrity Complete with practical projects such as developing text messaging systems and analyzing automotive key fob signals, this book gets you working with real digital signals fast. Whether you're a hardware hacker developing your own RF devices, a security researcher examining vulnerabilities in wireless systems, or a ham radio enthusiast exploring the digital realm, Hacking Digital Radios will show the way.