Full-Duplex Wireless using USRP N210

Description

In this tutorial, we'll use node11-10 in the main grid (equipped with a USRP N210) to transmit and receive a single frequency over the air to demonstrate full-duplex wireless capability using the Columbia ​FlexICoN's Gen-1 Frequency-Flat Amplitude- and Phase-based RF Canceller. Pictures of the FlexICoN RF canceller and node11-10 in the main grid equipped with full-duplex capability are below:

Figure 1: The ORBIT-FlexICoN Full-Duplex Node
a.) The FlexICoN RF Canceller	b.) Full-Duplex SDR at node11-10 in the ORBIT grid

For more information, please read

20. Chen, J. Zhou, N. Grimwood, R. Fogel, J. Marasevic, H. Krishnaswamy, and G. Zussman, “Demo: Full-duplex Wireless based on a Small-Form-Factor Analog Self-Interference Canceller,” in Proc. ACM MobiHoc'16, 2016. ​PDF

Please email Tingjun Chen (tc2668 [at] columbia.edu) if you are using (or plan to use) the full-duplex node, or if you have any questions. We also thank Mahmood Baraani Dasterjerdi and Steven Alfano for their great contributions.

Hardware / Software Resources Utilized

1. USRP N210 with node11-10 in the ORBIT main grid
2. SUB-20: The SUB-20 is a multi-interface USB adapter for providing popular interfaces between PC (USB host) and different hardware devices. Specifically, we use the SPI module on SUB-20 to control and configure our hardware. The user manual can be found ​here.
3. UHD
4. The Eigen C++ Library: The Eigen C++ library is used for basic algebra in channel estimation and digital self-interference cancellation. The Eigen releases can be found on the ​Eigen website. We used the latest stable release Eigen 3.3.4 through our testings and experiments.

All the source code is publicly available at ​here.

Set Up

Before you can access the testbed, you need to ​make a reservation and get it approved by the reservation service. After receiving the reservation's confirmation (approval) email:

• Login into reserved domain:

  ssh username@conslole.grid.orbit-lab.org
  

• Make sure that the full-duplex node is powered down for loading the desired image:

  omf tell -a offh -t node11-10
  

• Load an image on the node (this process can take about a few minutes so please be patient):

  omf load -i orbit-flexicon.ndz -t node11-10
  

• Turn on the node:

  omf tell -a on -t node11-10
  

• Login into the node:

  ssh root@node11-10
  

After login into the node, there is a flexicon_orbit folder under the home directory of node11-10 which contains the source code of this example. You can always retrieve the most recently updated code from ​here.

Run the Experiments

You will need to login into node11-10 in two (2) separate terminal windows lo for running the experiments: one for the main full-duplex transceiver program and one for controlling the RF canceller