RFNoC Spectrum Sensing

Description

This tutorial shows how to use the RFNoC Spectrum Sensing block(CE) to plot receive power spectrum from multiple USRP X310s on ORBIT grid.

Set Up

Make a reservation on the ​Orbit Scheduler for using the grid.

Prepare Receive Node

• Load prasanthi-rfnoc-specsense-9-14.ndz on an ORBIT node.

  omf load -i prasanthi-rfnoc-specsense-9-14.ndz -t node1-19
  

• Once imaging is done, turn the node on

  omf tell -a on -t node1-19
  

• Wait for the node to turn on and log in

  ssh root@node1-19
  

Prepare Receive USRPs

• Pick USRP X310s from the MIMO racks 23-1…8, 23-11…18 and load spectrum sensing FPGA image on them.

  uhd_image_loader --args="addr0=10.10.23.11,addr1=10.10.23.12,addr2=10.10.23.13,add4=10.10.23.14" --fpga-path="/root/bit/x310_spec_sense_2ddc_1duc_7_14.bit"
  

• Power cycle USRPs so that the new FPGA image is active

  omf tell -a offh -t node23-11
  omf tell -a on -t node23-11
  

Prepare Transmit Node

Any source can be used to transmit a test waveform. In this tutorial, a spectrum spreader RFNoC block is being used to generate wideband PN signal.

• Load prasanthi-channel-sounder.ndz on an ORBIT node.

  omf load -i prasanthi-channel-sounder.ndz -t node1-20
  

• Once imaging is done, turn the node on

  omf tell -a on -t node1-20
  

• Wait for the node to turn on and log in

  ssh root@node1-20
  

Prepare Transmit USRP

• Pick a USRP X310 for transmitting, and load the spectrum spreader FPGA image

  uhd_image_loader --args="addr=10.10.23.17" --fpga-path="/root/bit/x310_spreader_4_28.bit"
  

• Power cycle the USRP so that the new FPGA image is active

  omf tell -a offh -t node23-17
  omf tell -a on -t node23-17
  

Set up SSH tunnel from your local port 5100 to grid.orbit-lab.org:5100

ssh -L 5100:grid.orbit-lab.org:5100 username@grid.orbit-lab.org

Set up a web proxy for the receive node

Verify that Webproxy is running (this is required for remote web based streaming)

nilanjan@.grid:~$ run-websock 5100 10.10.1.19:5100 --daemon
WebSocket server settings:
  - Listen on :5100
  - Flash security policy server
  - No SSL/TLS support (no cert file)
  - Backgrounding (daemon)