Re: [Discuss-gnuradio] transmit file with qpsk on e310

[Timothée COCAULT]

I think you should use differential encoding with DPSK Mod/DPSK Demod block because the receiver doesn't know the phase used.

Also, if you want to test the reliability of your flowgraph, you can replace your USRP source and sink with a Channel Model and play with the frequency, noise, etc...

Timothée.

Le dim. 29 nov. 2015 à 5:53, Ekko <address@hidden> a écrit :

hi 

follow your suggestion ,i use the "PSK mod" and "PSK demod",just like

is it clear，if not i will upload my grc file

​now,i set the vector source ,vector="0,1,2,3,4,5,6,7,8,9"

and i transmit it,receive it into a file

i found that in my file,it is not the sequence in vector source

0123456789,just the part of this sequence.i think that some number was lose.(is it right?)

i want to know how to Reduced this lost of number,for example some block need to be added.

the "psk demod"  got the freq and phase correction itself.

and waht is the delimited messages.

thank you 

--Ekko

2015-11-29 1:26 GMT+08:00 Timothée COCAULT <address@hidden>:

Hi,

First you should have a look at the PSK demodulation tutorial : http://gnuradio.org/redmine/projects/gnuradio/wiki/Guided_Tutorial_PSK_Demodulation .

It uses a Polyphase Clock Sync between the receiver and the constellation decoder.

Alternatively, you can use the Constellation Receiver which is a Constellation Decoder with freq and phase correction.

But if you want a more simple solution, the DPSK Mod/DPSK Demod blocks seems like the best solution.

When your receiver works, you can have a look at the Packet Operators to send delimited messages.

Good luck.

Le sam. 28 nov. 2015 à 9:55, Ekko <address@hidden> a écrit :

hello all

i want to transmit a file with the way of  QPSK

this is my send grc

file source----repack bits-----chunks to symbol-----multile const------uhd_ink

this is my receive grc

uhd_source-----constellation decoder-----repack bits-----file sink

next is the "qt gui constellation sink" of the oupotput of 

chunks to symbol in the send

next is the output of UHD_source in recieve "qt frequence sink""qt gui constellation sink"

in this picture ,i think the recieve got the signal,but i do not know the constellation mean,

next is the set of my uhd_source and uhd_sink

source

sink

​
​my problem is that my recieve file is completely different with the source file

i use simulation way (no uhd),the recieve is same as source,

so i think there is some block needed between the constellation coder and uhd_source,for example the sync block

hope someone knows how to solve this sync problem or how to transmit a file with QPSK on e310 with the  antenna

thank you 

---Ekko​