Neil MacEwen, MathWorks
The Pluto Radio and Xilinx® Zynq®-Based Radio support packages from Communications Toolbox™ can be used to repeatedly transmit arbitrary signals onto the air using Software Defined Radio (SDR) hardware. Using a simple-to-use MATLAB® interface, any signal can be generated and downloaded onto the SDR hardware, from where it is repeatedly transmitted over the air. In parallel, the signal can be received and easily visualized, so the channel effects are visible on the received signal. First, a few lines of MATLAB code from WLAN Toolbox™ are used to generate a fully standard-compliant WLAN beacon signal. The SDR hardware is easily configured with a simple MATLAB object, and the generated signal is loaded onto the connected SDR hardware. The signal is then repeatedly transmitted onto the air. It is shown how the beacon signal appears on a laptop display as it scans for WiFi networks. In parallel, Simulink® is used to show how the spectrum of the transmitted signal can be viewed in real time. Next, a fully custom OFDM waveform is generated using the Communications Toolbox Waveform Generation App. Some null pilot signals are easily inserted to give the spectrum a distinctive shape before the signal is again loaded onto the attached SDR hardware and transmitted onto the air. The spectrum analysis setup from before is used in parallel to see the OFDM signal being transmitted in real time.