Changes between Version 10 and Version 11 of Tutorials/k0SDR/Tutorial04a

Timestamp:

Dec 19, 2012, 4:19:40 PM (11 years ago)

Author:

nilanjan

Comment:

—

Tutorials/k0SDR/Tutorial04a

@@ -9 +9 @@
  3. spectrum: application on node to set up & collect data from USRP2 and send to OML server / local file for recording in database file.
  4. spectrum_console: application on console to configure & initiate spectrum sense application on node.
- 5. Orbit's Arbitrary Waveform Injection System: used to inject noise or simple signal into RF environment. More information of this generator can be found [http://www.orbit-lab.org/wiki/Documentation/ArbInterference here].
+ 5. Orbit's Arbitrary Waveform Injection System: used to inject noise or simple signal into RF environment. [http://www.orbit-lab.org/wiki/Documentation/ArbInterference More information of this generator can be found here.]
 
 == Set up ==
@@ -49 +49 @@
 }}}
 
-== Spectrum sensing the noise floor ==
+== Spectrum sensing with multiple nodes at different frequencies ==
 
  * To view the available parameters for the console application
@@ -58 +58 @@
  * The first run will demonstrate how to use the sensing application on multiple nodes centered at different frequencies. In this case we will not inject noise into the environment. Check the following page to view nodes corresponding to [http://www.orbit-lab.org/wiki/Documentation/USRP2_hw_map usrp n210].[[BR]]
  In this case we'll be sensing on node3-3, node8-8, node13-13 on the frequencies 5.0 GHz, 5.1 GHz, 5.2 GHz respectively.[[BR]]
- Sampling rate option (''--rate 16e6'') yields a bandwidth of 8MHz.[[BR]]
+ Sampling rate option (''--rate 8e6'') yields a bandwidth of 4MHz.[[BR]]
  The fft size (''--num-bins 1024'') corresponds to a 1024 point fft.[[BR]]
  The time option (''--time 5'') runs the application for 5 seconds.
  Since the ''--oml file'' option is used the collected data will be store on the node locally.[[BR]]
 {{{
-nilanjan@console.grid:~/UHD/SPECTRUM/w$ ./spectrum_console --rate 16e6 --num-bins 1024 --time 5 --oml file --node node3-3,node8-8,node13-13 --freq 5.0e9,5.1e9,5.2e9
+nilanjan@console.grid:~/UHD/SPECTRUM/w$ ./spectrum_console --rate 8e6 --num-bins 1024 --time 5 --oml file --node node3-3,node8-8,node13-13 --freq 5.0e9,5.1e9,5.2e9
 }}}
 
- * The recorded spectrum data is stored in a file under the root directory on each of the nodes. Copy that data file from the node to the console and check the contents. The following will copy the data collect from node3-3.
+ * The recorded spectrum data is stored in a file under the root directory on each of the nodes. Copy that data file from the node to the console and check the contents. Each node will have its own file: /root/spectrum_measurement_nodex-y. [[BR]]
+ The following will copy the data collect from node3-3 to the console.
 {{{
-nilanjan@console.grid:~/UHD/SPECTRUM/w$ scp root@node3-3:/root/spectrum_measurement_node3-3 .
+nilanjan@console.grid:~/UHD/SPECTRUM/w$ scp root@node8-8:/root/spectrum_measurement_node8-8 .
 }}}
 
  * The contents of the file is very long and is in a database format. The full contents of an example run can be view [http://www.orbit-lab.org/attachment/wiki/Documentation/GNURadio/Tutorials/FFTSpectrum/spectrum_measurement_node8-8 here].
 
- * Plot of the noise floor across multiple node. 
+ * Plot of the noise floor at 5.0GHz, 5.1GHZ and 5.2 GHz is shown below.
+  || [[Image(noise_floor.png, width=500px)]] ||
+
+== Frequency detection with multiple nodes.
+
+ * This will demonstrate using the waveform generator to create a signal at 5.002 GHz and using the USRPs to detect & record the signal. From the grid console enter the following to configure & run the waveform generator at 5.002 GHz with a -1 dBm power level.
+{{{
+nilanjan@console.grid:~/UHD/SPECTRUM/w$ wget -qO- http://instrument1.orbit-lab.org:5012/interference/stop
+OK
+nilanjan@console.grid:~/UHD/SPECTRUM/w$ wget -qO- http://instrument1.orbit-lab.org:5012/interference/set?frequency=5.002\&power=-1
+OK
+nilanjan@console.grid:~/UHD/SPECTRUM/w$ wget -qO- http://instrument1.orbit-lab.org:5012/interference/start
+OK
+}}}
+
+ * Now use the node3-3, node8-8 and nod13-13 to record data at frequency 5.0 GHz with a sampling rate of 16e6.
+{{{
+nilanjan@console.grid:~/UHD/SPECTRUM/w$ ./spectrum_console --rate 16e6 --num-bins 1024 --time 5 --oml file --node node3-3,node8-8,node13-13 --freq 5.0e9
+}}}
+
+ * Each node will have it owns data file as before. At zip file with this data can be downloaded here.
+
+ * The extracted data and plot of the signal detection is shown below.
+  || [[Image(f5.002.png, width=500px)]] ||