# USRP source block queries

**URL:** <https://www.ruby-forum.com/t/usrp-source-block-queries/237851>\
**Category:** GNU Radio\
**Created:** [December 3, 2013, 6:20pm UTC](https://www.ruby-forum.com/t/usrp-source-block-queries/237851 "2013-12-03T18:20:29Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![Detlef\_R](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/d/58f4c7/32.png) [@Detlef\_R](https://www.ruby-forum.com/u/Detlef_R)\
**Post date:** [December 3, 2013, 6:20pm UTC](https://www.ruby-forum.com/t/usrp-source-block-queries/237851/1 "2013-12-03T18:20:29Z")

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Hello.

I am a graduate student researcher with the Satellite Technology Lab at  
The  
University of Texas at Arlington.

I’ve been trying to find out the working behind the USRP source block. I  
did find some basic description (like what it does in a few sentences  
and  
the arguments it accepts) in the GNU radio documentation but could not  
find  
detailed information. My queries include the following:

1: How exactly does the USRP source block process an incoming signal?  
Meaning, what kind of signal processing techniques does it use?  
2: What kind of sampling techniques does the USRP block use on the  
incoming signal?

I’ve looked into the Python (Sphinx) and C++ (Doxygen) documentation  
provided by GNU radio but was unable to find a thorough design document  
on  
the USRP source block.

I was wondering if someone could please provide a detailed description  
of  
the USRP source block including it’s signal processing and sampling  
techniques.  
I am hoping to save all the time and effort that would go into going  
through all the USRP codes line by line.

Please pardon me if the above problem seems trivial or simplistic. I am  
very new to GNU radio and would really appreciate some direction.

Thanks and regards,  
Namrata Kamte

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**Author:** ![Namrata\_Kamte](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/n/b5ac83/32.png) [@Namrata\_Kamte](https://www.ruby-forum.com/u/Namrata_Kamte)\
**Post date:** [December 3, 2013, 7:01pm UTC](https://www.ruby-forum.com/t/usrp-source-block-queries/237851/2 "2013-12-03T19:01:24Z")

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Hi Namrata,

USRPs use UHD as their hardware driver. [1] provides lots of  
documentation  
about USRPs.

Have fun and happy hacking  
Johannes

[1] [http://code.ettus.com/redmine/ettus/projects/uhd/wiki](http://code.ettus.com/redmine/ettus/projects/uhd/wiki)

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**Author:** ![Namrata\_Kamte](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/n/b5ac83/32.png) [@Namrata\_Kamte](https://www.ruby-forum.com/u/Namrata_Kamte)\
**Post date:** [December 3, 2013, 7:27pm UTC](https://www.ruby-forum.com/t/usrp-source-block-queries/237851/3 "2013-12-03T19:27:44Z")

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Hi Namrata,

I think you’re mixing up a lot of concepts. A “block” is a software  
unit in the GNU Radio framework. Please read the introductory pages of  
[gnuradio.org](http://gnuradio.org) to understand blocks better.  
A USRP is a hardware device; it does the sampling, which, of course,  
is a functionality of hardware. It, in fact, does a lot of signal  
processing. To learn about the properties of the USRP devices, read  
the website of the manufacturer Ettus and the UHD driver wiki.

The USRP source block doesn’t do any “signal processing”; it just gets  
the samples from the USRP driver (called UHD) into GNU Radio.

Greetings,  
Marcus

On 03.12.2013 17:34, Namrata Kamte wrote:

> description of the USRP source block including it’s signal
> 
> \_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_ Discuss-gnuradio  
> mailing list [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid)  
> [Discuss-gnuradio Info Page](https://lists.gnu.org/mailman/listinfo/discuss-gnuradio)

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