Changes between Initial Version and Version 1 of Tutorials/k0SDR/Tutorial14

Timestamp:

Sep 8, 2015, 6:08:27 PM (9 years ago)

Author:

prasanthi

Comment:

—

Tutorials/k0SDR/Tutorial14

@@ +1 @@
+== Spectrum sensing with USRP2 and wiserd ==
+
+[[TOC(Tutorials/k0SDR*)]]
+
+=== Description ===
+This tutorial will utilize Wiserd to set up USRPs for signal transmission and reception. 
+
+=== Hardware / Software Resources utilized ===
+ 1. Grid nodes with a USRP2 connect via Ethernet.
+ 2. ''ubuntu-14-04-64bit-sdr.ndz'': disk image loaded onto nodes.
+ 3. [http://wiser.orbit-lab.org/wiki/wiser/mSoftware/aWiserd Wiserd] - interface to configure and stream data to/from USRPs.
+ 4. octave - generate transmit data file and plot received data file.
+
+
+=== Set up ===
+ * To get started first make a reservation on the [https://www.orbit-lab.org/schedule/ Orbit Scheduler] for using the Grid.
+
+ * After logging into grid console, make sure all nodes are turned off
+{{{
+nilanjan@console.grid:~$ omf tell -a offh -t system:topo:all
+}}}
+
+ * Verify state of node before continuing. Make sure all nodes are in the POWEROFF state.
+{{{
+nilanjan@console.grid:~$ omf stat
+}}}
+
+ * Image nodes
+{{{
+nilanjan@console.grid:~$ omf load -i ubuntu-14-04-64bit-sdr.ndz -t node20-20,node19-19,node8-8 -r 20
+}}}
+
+ * After nodes are imaged, verify that nodes are in POWEROFF state. Otherwise issue the following to turn them off for a reboot
+{{{
+nilanjan@console.grid:~$ omf tell -a offh -t system:topo:all
+}}}
+
+ * Turn nodes back on and verify they are in POWERON state
+{{{
+nilanjan@console.grid:~$ omf tell -a on -t node20-20,node19-19,node8-8
+}}}
+
+In this example node8-8 and node19-19 is used as the transmitting nodes and the node20-20 as the receiver
+
+=== Generate signal source file using octave ===
+
+On each transmiting node, create a signal file using octave. You can use the scripts provided here as an example. On node8-8 create a file ''s1.bin'' using the lines below
+{{{
+root@node8-8:~# cd wiserd
+root@node8-8:~/wiserd# octave
+octave:1> signal = fGenFDSignal(256,50,10,'1half');
+octave:2> saveToWiserdFile(signal,'s1.bin');
+octave:3> exit
+}}}
+
+The signal will look something like the following in the frequency domain - notice the first half of the spectrum is populated:
+  || [[Image(s1.png, width=500px)]] ||
+
+Create a similar signal on node19-19 but with the 2nd half of the spectrum populated
+{{{
+octave:1> signal = fGenFDSignal(256,50,10,'2half');
+octave:2> saveToWiserdFile(signal,'s2.bin');
+}}}
+  || [[Image(s2.png, width=500px)]] ||
+
+
+=== Set up transmitting node ===
+
+
+ * ssh into each node and start the wiserd interface:
+{{{
+root@node8-8> wiserd
+linux; GNU C++ version 4.8.2; Boost_105400; UHD_003.008.002-86-g566dbc2b
+
+-- Opening a USRP2/N-Series device...
+-- Current recv frame size: 1472 bytes
+-- Current send frame size: 1472 bytes
+-- Detecting internal GPSDO.... No GPSDO found
+-- Successfully tuned to 900.000000 MHz
+--
+-- Successfully tuned to 900.000000 MHz
+--
+Ready!
+>
+}}}
+
+ * At the wiserd prompt set the carrier frequency, sampling rate & gain. Then link the transmitter to the signal source which is the binary file generated in octave from prior step:
+{{{
+> --uhd_tx_freq 700e6 --uhd_tx_rate 5e6 --uhd_tx_gain 20 --tran_wavefilename s1.bin
+-- Successfully tuned to 700.000000 MHz
+uhd_tx_freq 700000000
+uhd_tx_gain 20
+uhd_tx_rate 5000000
+> --addmodule signalfromfile
+Consumer signalfromfile added
+LLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLL
+>
+}}}
+
+In order to set parameter values, multiple arguments can be used in one line:
+
+ ''--uhd_tx_freq'' set carrier frequenct to 700MHz
+
+ ''--uhd_tx_rate'' set sampling rate to 5M samples/sec
+
+ ''--uhd_tx_gain'' set transmit gain to 20dB.
+
+ ''--tran_wavefilename''  tells the links the transmitter source to a binary filename.
+
+''--addmodule signalfromfile'' opens the above filename, reads the samples and streams to the usrp.
+
+At this point the USRP will continuously transmit the signal util the delete command is issued:
+
+ ''--delmodule signalfromfile'' stops tranmitting signal.
+
+
+Now set up the transmitter on node19-19 using similar commands.
+
+
+
+=== Set up receiving node(s) ===
+On the receiving node (node20-20), run wiserd to capture a snapshot of the signal from both transmitters.
+{{{
+root@node20-20> wiserd
+linux; GNU C++ version 4.8.2; Boost_105400; UHD_003.008.002-86-g566dbc2b
+
+-- Opening a USRP2/N-Series device...
+-- Current recv frame size: 1472 bytes
+-- Current send frame size: 1472 bytes
+-- Detecting internal GPSDO.... No GPSDO found
+-- Successfully tuned to 900.000000 MHz
+--
+-- Successfully tuned to 900.000000 MHz
+--
+Ready!
+> --uhd_rx_freq 700e6 --uhd_rx_rate 5e6 --uhd_rx_gain 20 --recv_running_time 1000 --recv_output_filename rx_signal
+-- Successfully tuned to 700.000000 MHz
+--
+recv_output_filename rx_signal
+recv_running_time 1000
+uhd_rx_freq 700000000
+uhd_rx_gain 20
+uhd_rx_rate 5000000
+> --addmodule timesamplestofile --timed
+Consumer timesamplestofile added
+Consumer timesamplestofile finished
+
+> exit
+}}}
+
+
+Here the set command has an additional argument to limit capturing to 1000 milliseconds:
+
+ ''--recv_output_filename'' set receiving signal filename.
+
+ ''--recv_running_time''    set receiver run time in milliseconds. (optional)
+
+The --addmodule command options
+
+ ''--addmodule timesamplestofile'' streams data from receiver to file
+
+ ''--timed''             runs receiver for the specified amount of time. (optional)
+
+Received signal file name will automatically be appended with the frequency, rate and gain:
+{{{
+root@node20-20> ls -ltr *.bin
+-rw-r--r-- 1 root root 40003072 May 21 10:56 rx_signal_freq700000000_rate5000000_gain20.bin
+}}}
+
+Use octave to view the spectrum image:
+{{{
+octave:1> fReconFDSignal(readWiserdFile('rx_signal_freq700000000_rate5000000_gain20.bin', 256*500), 256);
+}}}
+
+Received signal should look simiar to
+  || [[Image(signal.png, width=500px)]] ||