Packet encoder and decoder

Hi list,

I have created a dqpsk transceiver with two usrp2 boards. This is my
flow graph in GRC.

Tx
vector source -> packet encoder -> dpsk modulator(-m dqpsk,
4samples/symbol) -> constant multiplier (*0.1) -> UHD-USRP sink

Rx
UHD-USRP source -> Low pass filter (Hann window) -> dpsk demodulator ->
packet decoder -> file sink

When i run the graph, I dont receive anything at the file sink. If I
remove packet encoder and decoder, i do receive transmitted vector with
few errors. What is this problem? May I know what packet encoder and
decoder doing exactly?

Even if the demodulated data are wrong, i’m still expecting something at
packet decoder. If i just connect modulator to demodulator, it’s working
fine.

ANT

Hi, have you solved your problem with the packet decoder block in grc,
which is don’t working (no output) in the output port ,when the decoder
was added to the flow graph. Now i am meeting the same question ,so can
u give me some guide. thank u ,very much !!! please reply the email
,[email protected].
thank u!

Jevons Z. wrote in post #1049432:

Hi, have you solved your problem with the packet decoder block in grc,
which is don’t working (no output) in the output port ,when the decoder
was added to the flow graph. Now i am meeting the same question ,so can
u give me some guide. thank u ,very much !!! please reply the email
,[email protected].
thank u!

Have anyone of u solved the problem. I am also facing the same problem.
Thanks in advance.

Regards
M.G.Praveen kumar