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RFNoC is a network-distributed heterogeneous processing tool with a focus on enabling FPGA processing in USRP devices. It allows you to move data on and off of an FPGA in a transparent way, thus enabling seamless use of both host-based and FPGA-based processing in an application. The result is a much simpler way to leverage FPGA processing capabilities and IP in your application which can scale across multiple FPGAs and devices across a network.

Signal processing algorithms are contained modules known as "Computation Engines" or "RFNoC Blocks", and an interface wrapper is provided to encapsulate existing or external IP to use with RFNoC. This allows you to import Xilinx™ CoreGen™ IP blocks, for example, and use them immediately in your RFNoC application. The internals of a RFNoC block are wholly independent from any other block, and can be designed with any tool that supports AXI stream interfaces, including VHDL, Verilog, and Xilinx™ Vivado™ HLS.

We are quickly building out the library of ready-to-use RFNoC blocks and already have many available, including the blocks necessary for an OFDM stack (e.g., detection, synchronization, equalizer, packet demodulator).

RFNoC is integrated with the UHD™ software, and all USRP devices from the third-generation on (X300 Series, E300 Series) are supported by RFNoC out-of-the-box. Like UHD, RFNoC is also Free and Open Source Software, and the full source code can be found in our public code repositories.


Framework and Data Flow Example

Below is a figure of the RFNoC stack.

rfnoc stack.png

The example below shows basic data flow of an RFNoC application. While this shows one possible data flow, there are many possible combinations from Host block to FPGA block, FPGA block to Host block, Host to Host, FPGA to FPGA, etc.

gr rfnoc ex1.png

Supported Devices

  • E310/E312
  • X300/X310

Sample of Available Blocks

  • FIFO
  • FFT
  • FIR
  • fosphor (real-time spectrum analyzer)
  • Decimator (Keep 1 in N)
  • Log Power Calculator
  • Radio Interface
  • Vector IIR (moving average)
  • Window multiplier (for FFT)
  • OFDM: Burst detection + synchronization, equalizer, packet demodulator
  • and more...

Blocks Included with Default FPGA Images

The following images have the corresponding RFNoC blocks (Computation Engines):

Image Name Included Blocks




2x DDC, 2x DUC


DUC, DDC (one channel), fosphor, window, fft, 2x AXI FIFOs


DUC, DDC (one channel), fosphor, window, fft, 2x AXI FIFOs, Keep One in N, FIR, Siggen


1x DDC, 1x DUC
usrp_e310_fpga_RFNOC.bit (sg1 version)


fosphor, window, fft, 2x AXI FIFOs, FIR

RFNoC Resources