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== Spectrum visualization with Fosphor ==

=== Description ===

This tutorial illustrates use of [https://archive.fosdem.org/2015/schedule/event/rfnocfosphor/attachments/slides/804/export/events/attachments/rfnocfosphor/slides/804/fosdem2015_rfnoc_fosphor.pdf RFNoC Fosphor block for spectrum visualization]. RFNoC Fosphor block is the FPGA accelerated version of [https://projects.osmocom.org/projects/sdr/wiki/Fosphor gr-fosphor (CPU/GPU version)]. As any other RFNoC blocks, RFNoC Fosphor can be instantiated on 3rd generation USRP devices, and can be used in conjunction with gnuradio-companion(GRC) on the host computer. This tutorial demonstrates GRC RFNoC Fosphor application on USRP-2974s in [COSMOS testbed wiki:Hardware/sdr/usrp2974] and USRP X310s in [ORBIT]. 

Running a GRC application on a testbed node requires using graphical user interface(GUI) over SSH. This tutorial also illustrates use of [https://mobaxterm.mobatek.net/ MobaXterm] and jumphost to setup X forwarding for accessing GUI over SSH.

=== Prerequisites ===
In order to access the test bed, create a reservation and have it approved by the reservation service. Access to the resources is granted after the reservation is confirmed. Please follow the process shown on the COSMOS [wiki:GettingStarted getting started] page to get started. 

=== Resources required ===
1 USRP-2974 (sdr2-md1 or sdr2-s1-lg1) on COSMOS SB1.
=== Tutorial Setup ===

Follow the steps below to gain access to the [wiki:/hardware/Domains/sb1 sandbox 1 console] and set up nodes with appropriate images. 
 1. If you don't have one already, sign up for a [https://www.cosmos-lab.org/portal-2/ COSMOS account]
 1. [wiki:/GettingStarted#MakeaReservation Create a resource reservation] on sandbox 1
 1. [Documentation/Short/Login Login] into sandbox 1 console (console.sb1.cosmos-lab.org) with two SSH sessions. 
 1. Make sure all the nodes and devices used in the experiment are turned off:
{{{#!shell
omf tell -a offh -t sdr2-s1-lg1  
}}}
 1. Load rfnoc_fosphor_3_15.ndz on sdr2-s1-lg1.  
{{{#!shell
omf load -i rfnoc_fosphor_3_15.ndz -t sdr2-s1-lg1
}}}
 1. Turn the SDR on and check the status
{{{#!shell
omf tell -a on -t sdr2-s1-lg1
}}}
{{{#!shell
omf stat -t sdr2-s1-lg1
}}}


=== Experiment Execution ===
=== Configure !MobaXterm for node access ===

[[Image(nodessh.png, width=300px)]]
[[Image(jumphost.png, width=300px)]]

=== Prepare the node ===

==== Run gr-fosphor ====
{{{
gnuradio-companion  /root/gr-ettus/examples/rfnoc/rfnoc_fosphor.grc
}}}

{{{
root@sdr2-s1-lg1:~# gnuradio-companion  /root/gr-ettus/examples/rfnoc/rfnoc_fosphor.grc
<<< Welcome to GNU Radio Companion 3.7.13.5 >>>

Block paths:
        /usr/local/share/gnuradio/grc/blocks

Loading: "/root/gr-ettus/examples/rfnoc/rfnoc_fosphor.grc"
>>> Done

}}}
[[Image(gr-fosphor.png, width=800px)]]
[[Image(display.png)]]