I have been playing with two simple flow-graphs in gnuradio-companion, one for dbpsk transmitter and other for dbpsk receiver. The transmitter flow-graph
is:
vector source -- > packet encoder -- > dpsk modulator -- > uhd: usrp sink
The receiver flow-graph is:
uhd: usrp source --> low-pass filter --> dpsk demodulator --> packet decoder --> file sink
The vector source is given a vector {10,20,30} as input, repeat is set to "yes"; in the packet encoder, samples/symbols is set to 8, bits/symbols is set to 1 (because dbpsk scheme is to be used), pad for usrp is set to "yes" and payload is set to "0"; in the dpsk modulator, samples/symbols is set to 8 and all other
parameters are left unchanged.
At the receiver, I use matching/appropriate parameters inside the dpsk demodulator and low-pass filter blocks. And the sampling rate is set to be 1M Sps on both transmitter and receiver.
Now, the issue is that I do not receive any decoded symbols in the file sink. Previously, when I was running the two flow-graphs on two computers with Ubuntu 11.04 and gnuradio-3.4 on them, everything was just fine, but as soon as I have upgraded the OS and gnuradio to 11.10 and 3.5 versions, I do not get anything in the file sink.
Could someone provide a suggestion in this regard?
Thanks.
Jon