GUILLAUME WILLIAM
BRES
Software Defined Radio on the Zynq
Zynq is a entirely programmable System On Chip produced by Xilinx. It is one the most powerful chips embedding both a dual core CPU and an FPGA.
This application is rather complex: it involves HDL design to controll the radiomodem and the I/Q flow, a performant FPGA/Linux kernel interface and a high end DSP software.
Gnuradio:
In this application I am using the Gnuradio framework directly embedded on my Zedboard (zynq dev. board).
This was possible thanks to the work presented on the official Gnuradio on the Zynq page.
Principle: A digital data flow is coming into the FPGA thanks to the SX1255 radiomodem, it goes through our FPGA/Linux interface and reaches the Gnuradio framework (data source).
My Zedboard embedding the ZYNQ (Xilinx) and a SX1255 Radiomodem designed by Semtech.
The SX1255 is plugged in the FPGA and the two CPUs run a Linux image.
Turn your sound on for the second part of the video.
Video / demonstration:
#1. Demonstrates we are receiving accurate data: the FFT is computed by the "FFT GUI" block, we provide a 80 kHz continuous and frequency modulated flow.
#2. Demonstrates no sample is being missed: we output the results of the "Wide Band Frequency Modulation" demodulator block toward an external USB sound card. Once again, it is a 80 kHz continuous flow.
Check out the improvements made for this application on this page:
we managed to upgrade
to a 4 MS/s continuous flow, maximum
speed of our radiomodem.