Introduction

HybridSDR is a toolkit for building software-defined radio systems containing a mixture of software running on a general-purpose computer and gateware running an an FPGA. It allows the user to connect signal processing blocks graphically. Then, at runtime, the gateware design is assembled using the flexibility of Amaranth.

Crossings between the gateware and software domains are handled seamlessly. At runtime a custom USB device is built in gateware using LUNA.

The current proof-of-concept is provided as an out-of-tree module for GNU Radio, which includes a graphical interface to place & connect signal processing blocks and a large range of existing blocks to use. It targets the ECP5 FPGA on the Amalthea open-source radio platform.

Above is a screenshot from GNU Radio Companion, showing how the HybridSDR blocks can be used. Green lines represent connections in the gateware domain - these connections and blocks are built into a gateware bitstream at runtime. Green/black striped lines represent seamless connections across USB streams.