QPSK Voice Tx/Rx

Hello, I am working on a real time voice Tx/Rx using GNU Radio as
software and a USRP E110. I’m trying to do a QPSK Modulation and I have
consulted several models and forums and it seems everything is okay,
however at the moment of receiving signal, the audio on the receiver is
breaking up, and I want the audio sounds good. I thought it might be
because of some errors in synchronism and carrier recovery, so I added
the block MPSK Reciever, without any changes in the audio output. Is
anything I am missing? or Is any calculation or number wrong?

Could it be because of lack in processing? because I’ve tried the same
model with GMSK mod/demod blocks and the voice sounds good. I’ve
attached the flowgraphs of the Tx and Rx side for a better

I really appreciate your help and I look forward your reply.

P.S. I’ve also read that at the moment of involving blocks that work
with hardware (USRP Sink/Source) I have to skip the Throttle blocks, is
that true?

This forum is not affiliated to the Ruby language, Ruby on Rails framework, nor any Ruby applications discussed here.

| Privacy Policy | Terms of Service | Remote Ruby Jobs