Changes between Version 24 and Version 25 of Tutorials/k0SDR/Tutorial04a
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- Sep 30, 2014, 3:25:32 AM (10 years ago)
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Tutorials/k0SDR/Tutorial04a
v24 v25 1 = Spectrum sensing with USRP2=1 == Spectrum sensing with USRP2 == 2 2 3 == Description==3 === Description === 4 4 In this tutorial we'll use the USRPs on the grid for FFT-based spectrum sensing. Each USRP (centered on a frequency with specified bandwidth) will collect data into an OML server for post processing. For details on available USRP2s on the grid, please check [https://www.orbit-lab.org/status/orbit/ inventory status]. 5 5 6 == Hardware / Software Resources utilized==6 === Hardware / Software Resources utilized === 7 7 1. Grid nodes with a USRP2 connect via Ethernet. 8 8 2. ''ubuntu-12-04-uhd.ndz'': disk image loaded onto nodes. This image has all the precompiled - software required to configure the USRPs and analyze recorded data. The USRP2's interface with the node is already configured. … … 11 11 5. Orbit's Arbitrary Waveform Injection System: used to inject noise or simple signal into RF environment. [https://www.orbit-lab.org/wiki/Software/eAM/mInterf#InterferenceAggregateManager More information of this generator can be found here.] 12 12 13 == Set up==13 === Set up === 14 14 * To get started first make a reservation on the [https://www.orbit-lab.org/schedule/ Orbit Scheduler] for using the Grid. 15 15 … … 46 46 }}} 47 47 48 == Spectrum sensing with multiple nodes at different frequencies==48 === Spectrum sensing with multiple nodes at different frequencies === 49 49 50 50 * To view the available parameters for the console application … … 74 74 || [[Image(noise_floor.png, width=500px)]] || 75 75 76 == Frequency detection with multiple nodes.76 === Frequency detection with multiple nodes === 77 77 78 78 * 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. … … 102 102 || [[Image(f5.002.png, width=500px)]] || 103 103 104 == Spectrum sensing code==104 === Spectrum sensing code === 105 105 106 106 * The spectrum sensing code interfacing with the USRP is located in the node under the following directory: /root/uhd/host/examples/ - the two files of interest are CWriteOML_spectrum.h and spectrum.cpp. This version of the code uses an FFT to detect spectrum activity. This code can be modified/tweaked for testing other sensing schemes as well. 107 107 108 == Logging spectrum data directly to an OML server==108 === Logging spectrum data directly to an OML server === 109 109 110 110 * Spectrum data can also be logged directly to an OML server. In the above examples the data was recorded to a local file stored on the node itself. To log directly to an oml sever, run the ''spectrum_console'' application with the '''--oml''' option specified with an ip-address:port-number of the oml server. The following would record to the oml-server running on the grid console: