# Help required for dpsk\_loopback.grc **URL:** \ **Category:** GNU Radio\ **Created:** [March 4, 2015, 11:57am UTC](https://www.ruby-forum.com/t/help-required-for-dpsk-loopback-grc/234430 "2015-03-04T11:57:22Z")\ **Posts on this page:** 2\ **Page:** 1
**Author:** ![addis\_a](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/a/c4cdca/32.png) [@addis\_a](https://www.ruby-forum.com/u/addis_a)\ **Post date:** [March 4, 2015, 11:57am UTC](https://www.ruby-forum.com/t/help-required-for-dpsk-loopback-grc/234430/1 "2015-03-04T11:57:22Z")
Dear All, I am very new to GNU Radio and currently trying to explore the example grc blocks available with the package. For example, I tried to execute the example given in the example folder as “dpsk\_loopback.grc” (/home/ubuntu/examples/digital/demod/dpsk\_loopback.grc). I have following doubts: 1. There is no readme or document available which can explain about the total block or example in detail. Can I get any tutorial/document which will give complete info about all such examples?? i.e.Each grc example file to be explained in detail. If any such details are available, kindly give me the link for the same. 2. In the subject example, there is a signal source which is generating a cosine wave from 500Hz to 5KHz. This cosine wave after the throttle block is fed to packet encoder. Here, what is the role of packet encoder?? In the packet encoder block properties there are many fields like “samples/symbol”, “bits/symbol”, etc. These fields are generally related to data, not the analog signal which is fed to it. How does the packet encoder take cosine wave and use the fields like samples/symbol and bits/symbol??? Do we have any document which will explain in detail about all such blocks??? 3. I want to analyze the output of packet encoder. How is it possible?? Which block will you suggest to analyze the output??? 4. As I am very new to the GNU field and I quite poor in software domain, I would like to get some help in the beginners level. Please provide me any link, if it is available. Regards, SACHIN M. REGUNDWAR Hyderabad, India. ## :: DISCLAIMER :: The contents of this e-mail and any attachment(s) are confidential and intended for the named recipient(s) only. It shall not attach any liability on the originator or ECIL or its affiliates. Any views or opinions presented in this email are solely those of the author and may not necessarily reflect the opinions of ECIL or its affiliates. Any form of reproduction, dissemination, copying, disclosure, modification, distribution and / or publication of this message without the prior written consent of the author of this e-mail is strictly prohibited. If you have received this email in error please delete it and notify the sender immediately. Before opening any mail and attachments please check them for viruses and defect. THIS MAIL IS SCANNED BY ECIL IMSS FOR VIRUS AND SPAMS. ---
**Author:** ![SACHIN\_REGUNDWAR](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/s/e9c0ed/32.png) [@SACHIN\_REGUNDWAR](https://www.ruby-forum.com/u/SACHIN_REGUNDWAR)\ **Post date:** [March 4, 2015, 5:42pm UTC](https://www.ruby-forum.com/t/help-required-for-dpsk-loopback-grc/234430/2 "2015-03-04T17:42:24Z")
On Wed, Mar 4, 2015 at 5:18 AM, SACHIN REGUNDWAR [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) wrote: > will give complete info about all such examples?? i.e.Each grc example file > to be explained in detail. If any such details are available, kindly give > me the link for the same. Nope. The examples show you how to use the various blocks but don’t have write-ups on their own. You can find what each block does in the manual: > **[GNU Radio Manual and C++ API Reference: Main Page](https://www.gnuradio.org/doc/doxygen/)** > 1. In the subject example, there is a signal source which is generating a > cosine wave from 500Hz to 5KHz. This cosine wave after the throttle block > is fed to packet encoder. Here, what is the role of packet encoder?? In the > packet encoder block properties there are many fields like > “samples/symbol”, “bits/symbol”, etc. These fields are generally related to > data, not the analog signal which is fed to it. How does the packet encoder > take cosine wave and use the fields like samples/symbol and bits/symbol??? > Do we have any document which will explain in detail about all such > blocks??? It is a bit strange, I’ll admit, but that sine wave is just digital samples that are shaped like a sine wave. So passing them through as digitally modulated samples is the same as passing any value. > 1. I want to analyze the output of packet encoder. How is it possible?? > Which block will you suggest to analyze the output??? There are plenty of display widgets (QT or WX) that you can use here. Or dump it to a file and analyze the raw bytes anyway you know how. > 1. As I am very new to the GNU field and I quite poor in software domain, > I would like to get some help in the beginners level. Please provide me any > link, if it is available. > > Regards, > > SACHIN M. REGUNDWAR > Hyderabad, India. To get a good feel for GNU Radio: [http://gnuradio.org/redmine/projects/gnuradio/wiki/Guided\_Tutorials](http://gnuradio.org/redmine/projects/gnuradio/wiki/Guided_Tutorials) And for other reading: [http://gnuradio.org/redmine/projects/gnuradio/wiki/SuggestedReading](http://gnuradio.org/redmine/projects/gnuradio/wiki/SuggestedReading) Tom