On Mon, Apr 26, 2010 at 1:30 AM, devin kelly <dwwke...@gmail.com> wrote: > Hello Everyone, > I've made a basic DBPSK transmitter and receiver. I can receive ASCII > strings fine and the spectrum looks exactly as it should. > However, if I swap the DBPSK modulator/demodulator for the DQPSK > modulator/demodulator, my system breaks. I can no longer receive the same > strings and the spectrum looks very strange. It's much wider and triangular > shaped. > Same goes for the D8PSK system and the D16PSK system I recently was asking > about. > I believe marcin_w asked a similar question a few days ago and I haven't > seen a reply yet (am I wrong?) My question is, should I be doing something > different? Do I need to add in some extra block when I switch from DBPSK to > DQPSK? While searching old posts, I found some people talking about DQPSK > not working correctly, but that was about a year ago. > Any help would be greatly appreciated. > Devin
Well, you haven't really told us what you are doing (code-wise), so it's hard to tell... Have you compared your code to the dbpsk/dbpsk2 and dqpsk/dqpsk2 blocks in the source code? That might give you a hint. My best (blind) guess is that you are feeding the modulator the wrong number of bits per sample. You have to send a dbspk a chunk size of 1 bit / byte while the dqpsk takes 2 bits/byte chunks. Tom _______________________________________________ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
