Working with USRP - Universal Software Radio Peripheral

Description

In this tutorial we'll use the 2 USRPs on Sandbox 3 to transmit and receive a single frequency over the air. The UHD (UniversalSoftwareRadioPeripheral Hardware Driver) is used to communicate with the USRPs. This driver is used standalone to configure and enable the USRP for communication.

Hardware / Software Resources utilized

1. Sandbox 3 - consists of two nodes (node1-1 & node1-2). Each node has a USRP2 connect via Ethernet.
2. ubuntu-11-10-gnuradio.ndz: disk image loaded onto nodes. This image has all the precompiled - software required to configure the USRPs and analyze recorded data.
3. omf-5.2 / omf-5.3: used to image to nodes
4. octave: GNU version of MATLAB

Set up

• To get started first make a reservation on the ​Orbit Scheduler for using Sandbox 3

• After logging into sandbox 3 console, make sure both nodes are turned off

  nilanjan@console.sb3:~$ omf-5.2 tell offh all
  

• Verify state of node before continuing. Make sure all nodes are in the POWEROFF state.

  nilanjan@console.sb3:~$ omf-5.2 stat
  

• Image both nodes

  nilanjan@console.sb3:~$ omf-5.3 load -i ubuntu-11-10-gnuradio.ndz -t node1-1.sb3.orbit-lab.org,node1-2.sb3.orbit-lab.org
  

• After nodes are imaged, verify that nodes are in POWEROFF state. Otherwise issue the following to turn them off for a reboot

  nilanjan@console.sb3:~$ nilanjan@console.sb3:~$ omf-5.2 tell offh all
  

• Turn nodes back on and verify they are in POWERON state before proceeding

  nilanjan@console.sb3:~$ nilanjan@console.sb3:~$ omf-5.2 tell on all
  

Usage

• Once nodes are imaged, ssh into each node. Use the USRP2 on node1-1 as the transmitter and USRP2 on node1-2 as receiver.
  ssh into node1-1

  nilanjan@console.sb3:~$ ssh root@node1-1
  root@node1-1:~# cd uhd/host/build/examples/
  

ssh into node1-2

nilanjan@console.sb3:~$ ssh root@node1-2
root@node1-1:~# cd uhd/host/build/examples/

• The directory content like the following in both nodes

  root@node1-1:~/uhd/host/build/examples# ls
  benchmark_rate       latency_test      rx_samples_to_file  test_pps_input        tx_waveforms
  CMakeFiles           Makefile          rx_samples_to_udp   tx_bursts
  cmake_install.cmake  network_relay     rx_timed_samples    tx_samples_from_file
  CTestTestfile.cmake  rx_multi_samples  test_messages       tx_timed_samples