Changes between Initial Version and Version 1 of Tutorials/k0SDR/Tutorial22

Timestamp:

Apr 28, 2017, 10:28:14 PM (8 years ago)

Author:

tkuber

Comment:

—

Tutorials/k0SDR/Tutorial22

@@ +1 @@
+== Using 2 transmit or 2 receive antennas simultaneously==
+
+=== Description ===
+
+This example shows how to run two concurrent streams (RX and TX) on a single USRP device using UHD example on Orbit Wireless Testbed. The example assumes usage of any USRP with 2 TX/RX and 2 RX2 antennas such as X310 and B210. Information on SDR availability on particular nodes can be found on [https://www.orbit-lab.org/cPanel/controlPanel/start Orbit] by clicking on ''Status Page'', then on ''grid'', and then filtering the displayed nodes by SDR devices equipped.
+
+=== Set Up ===
+
+ 1. Make a reservation on [https://www.orbit-lab.org/cPanel/controlPanel/start Orbit] to use the Grid.
+ 2. Make sure the node of interest is turned off:
+{{{username@console.grid:~$ omf tell -a offh -t node18-2}}}
+ 3. Load the ''multiantennatutorial.ndz'' image onto the node. Note that this process might take several minutes.
+{{{username@console.grid:~$ omf load -i multiantennatutorial.ndz -t node18-2}}}
+ 4. Turn on the node. After issuing the "on" command, wait a couple of minutes for the node to boot up.
+{{{username@console.grid:~$ omf tell -a on -t node18-2}}}
+ 5. Connect to the node using SSH:
+{{{username@console.grid:~$ ssh -Y root@node18-2}}}
+
+Repeat this for 3 nodes, 1 USRP to behave as a multi-antenna transmitter and 2 USRPs to behave as multi-antenna receivers. 
+
+To make sure that the node can communicate with the USRP use the command uhd_find_devices and probe it for specs by uhd_usrp_probe similar to the example [http://www.orbit-lab.org/wiki/Tutorials/k0SDR/Tutorial00 here]. Use the appropriate input for the –-args argument. 
+
+=== Running the Experiment ===
+Go to the UHD examples folder to list the various available applications and check for rx_multi_samples_file and tx_multi_channel_file_pps_sync APIs.
+
+{{{ root@node18-2:~$ cd ./uhd/host/build/examples ls -ltr}}}
+
+Download the script attached at the bottom of the tutorial onto your console.
+Open the script and edit the file to correspond to the nodes you are working with. 
+
+To start the transmitter to constantly transmit packets: 
+{{{root@node18-2:~$ ./tx_multi_samples_file_pps_sync --args="type=b200" --file1 send_nogap_1.dat --file2 send_nogap_2.dat --spb 10000 --rate 2e6 --freq1 5.4e9 --freq2 5.4e9 --gain1 80 --gain2 80 --subdev="A:A A:B" --repeat --ref external}}}
+
+Start the two receivers using the script
+{{{username@console.grid:~$ omf exec multiantennareceiver.rb }}}
+
+There will be 2 new files on each of the receivers and can be found in the ''/uhd/host/build/examples'' folder as ''usrp_samples_1.dat'' and ''usrp_samples_2.dat''. 
+
+Observe the received signals using Octave at the receivers similar to the example [http://www.orbit-lab.org/wiki/Tutorials/k0SDR/Tutorial00 here].