Zynq-based WISER platform - Spectrum sensing with multiple nodes (OEDL)

Description

This tutorial demonstrates how to record spectrum on multiple nodes using an OEDL script.

Hardware / Software Resources utilized

1. SB6 nodes with WISER platform.
2. wiser_sb6_zedboard.ndz: disk image loaded onto nodes.
3. wiserd application - ​Check here for more info.

Spectrum sensing with an OEDL script

• Follow the start-up instructions to program and setup the FPGAs on both the nodes.
• The following OEDL script resides on the console of SB6 and can be used to run spectrum sensing on both the nodes at once.

  defProperty('radio',"zynq","")
  defProperty('rx_freq1', "800e6", "")
  defProperty('rx_freq2', "815e6", "")
  defProperty('rx_gain', "10", "")
  defProperty('rx_fft_bins',"256","")
  defProperty('rx_fft_scaling',"170","")
  defProperty('rx_fft_averaging',"256","")
  defProperty('start_fft',"0","")
  defProperty('time',10,"")
  
  require './wiserd.rb'
  
  defGroup('receiver', "node1-1.sb6.orbit-lab.org, node1-2.sb6.orbit-lab.org" ) do |node|
    node.addApplication("test:app:wiserd") do |app|
      app.setProperty('--radio',property.radio)
      if ((node).to_s.casecmp("node1-1.sb6.orbit-lab.org") == 0)
        app.setProperty('--zynq_rx_freq', property.rx_freq1)
      else
        app.setProperty('--zynq_rx_freq', property.rx_freq2)
      end
  
      app.setProperty('--zynq_rx_gain', property.rx_gain)
      app.setProperty('--zynq_fft_bins', property.rx_fft_bins)
      app.setProperty('--zynq_fft_scaling', property.rx_fft_scaling)
      app.setProperty('--zynq_avg_window', property.rx_fft_averaging)
      app.setProperty('--fft_engine',property.start_fft)
    end
  end
  
  onEvent(:ALL_UP_AND_INSTALLED) do |event|
    wait 5
    info "Starting the Receiver"
    group("receiver").startApplications
    wait 1
    property.start_fft = "1"
    wait property.time
    property.start_fft = "0"
    group("receiver").stopApplications
    Experiment.done
  end 
  

• The script here takes the receive center frequencies and run time as parameters along with the number of fft bins etc. Run the script by typing

  omf exec system:exp:zynq_spec_sense.rb --time 20
  

• Run tcpdump on the nodes to see packets coming from the zedboard to the node

  root@node1-2:~# tcpdump -i eth2
  

• FFT bin data is collected in /zynq_rx_fft.bin on each of the nodes. These files can be copied to the console and the spectrum can be plotted using an octave script.