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= Massive MIMO Channel Sounding =

=== Description ===
In this tutorial, we demonstrate the TDD 16x1 Massive MIMO channel sounding procedure using 1 Massive MIMO rack and 1 USRP-B210s in the [https://www.orbit-lab.org/wiki/Hardware/bDomains/aGrid ORBIT grid] and the [https://github.com/renew-wireless/RENEWLab/ RENEW Sounder software]

* The instructions of the RENEW Platform Sounder software can be found [https://docs.renew-wireless.org/dev-suite/design-flows/cpp/sounder/ here] under [https://docs.renew-wireless.org/license/ RENEW license].
* The COSMOS team contributes to adding the UHD support for the Sounder software under the [https://github.com/EttusResearch/uhd/blob/master/LICENSE.md UHD license].

Author: Zhenzhou (Tom) Qi, Duke University (zhenzhou.qi [at] duke [dot] edu)

Last updated: Jul. 07, 2022

=== Prerequisites ===

In order to access grid, create a reservation in grid 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 getting [https://wiki.cosmos-lab.org/wiki/GettingStarted started page] to get started.


=== Resources Required ===

* 1 Massive MIMO Rack ({{{node23-1}}} to {{{node23-8}}})
* 1 USRP-B210 ({{{node8-7}}})
* 1 Server ({{{node21-1}}})

=== Tutorial Setup ===

* 2 USRP-2974 ({{{sdr2-s1-lg1}}} and {{{sdr2-md1}}})
* 1 Server ({{{srv2-lg1}}})

=== Tutorial Setup ===

Follow the steps below to gain access to the grid 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 COSMOS sb2
 1. [Documentation/Short/Login Login] into sb2 console ({{{console.sb2.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,sdr2-md1,srv2-lg1
}}}
 1. Use the {{{baseline-gr.ndz}}} node image (see [https://wiki.cosmos-lab.org/wiki/UserGuide/DiskImages#DiskImages here] for the list of pre-defined images) with Ubuntu 18.04, UHD 3.15, and gnuradio 3.8. Load {{{baseline-gr.ndz}}} on the server.  
{{{#!shell
omf load -i baseline-gr.ndz -t srv2-lg1
}}}
 1. Turn all the required resources on and check the status
{{{#!shell
omf tell -a on -t sdr2-s1-lg1,sdr2-md1,srv2-lg1
}}}
{{{#!shell
omf stat -t all
}}}
 1. Make sure that the RF switch port is set to using the USRP 2974's. If some of the RF switch ports are set to "2", set them back to "1"
{{{#!shell
curl "am1.cosmos-lab.org:5054/rf_switch/set?name=rfsw-s1-lg1.sb2.cosmos-lab.org,rfsw-md1.sb2.cosmos-lab.org&switch=1,2,3,4&port=1"
}}} 
 1. {{{ssh}}} to the the same server from two terminals, use option -Y for using GUI.
{{{#!shell
[Terminal 1] ssh -Y root@srv2-lg1,
[Terminal 2] ssh -Y root@srv2-lg1
}}}

=== Experiment Execution ===