GNU Radio Companion GRC Graphical Flow Graph Design

GNU Radio Companion (GRC) Graphical Flow Graph Design for Software Defined Radio Josh Blum , Patrick Mulligan, A. Brinton Cooper What is GNU Radio? What is a Software Defined Radio? Motivation GNU Radio is a signal processing package, which is distributed under the terms of the GNU General Public License. The goal is to give ordinary software people the ability to 'hack' the electromagnetic spectrum, that is, to understand the radio spectrum and think of clever ways to use it. A software-defined radio (SDR) system is a radio communication system which can tune to any frequency band receive any modulation across a large frequency spectrum by means of programmable hardware which is controlled by software. The goal of software defined radio technology is the quick prototyping of a radio and transmitter that use any specified waveform, modulation, coding, and signal processing. • GNU Radio lacked a graphical interface Creating an FM Receiver in GRC Runtime Changeable Variables Graphical FFT Display • Using GNU Radio required a significant programming effort • ECE communications courses need experimental components Universal Software Radio Peripheral The Universal Software Radio Peripheral (USRP) is a low-cost, high speed implementation of Gnu Radio Hardware, developed by a team led by Matt Ettus. • USRP is configured entirely in software using GNU Radio • Removable Daughterboards with varying transmit & receive capabilities • Receive: DC to 2. 9 GHz • Transmit: DC to 30 MHz, 400 to 500 MHz, 800 MHz to 2. 9 GHz Abstracted SDR Hardware • Daughterboard specific implementation details are transparent to the User • Communicates with PC using USB 2. 0 (allows for 8 MS/s or 4 MHz of bandwidth) Automatic Gain Control What is GRC? FM Demodulator Available Signal Blocks Received Signal 1 k. Hz Tone Transmitted & Received using 21 MHz carrier Transmitted Signal GUI for creating flow-graphs in GNU Radio • Runs on most platforms: Linux, Mac. OS, Windows, Net. BSD • Used by amateur Radio Enthusiasts and students Worldwide • Used in communications courses at various Universities nationwide • Coded in the python programming language & GTK graphics • Graphical Sinks use WX graphics GRC is available for download http: //gnuradio. org/trac/wiki/GNURadio. Companion Special Thanks: A. Brinton Cooper, CER Technology Fellowship Grant, William R. Kenan Jr. Fund, GNU Radio