John, I did the simulation of the receive - transmit flow, bypassing the Usrp sink and source and putting in their place a Channel Model block and it works, meaning that you were right. This probably means that there is a problem with my USRP sink and source parameters, probably the sample rate, which I am currently investigating.
Vlad. John Andrews-5 wrote: > > On Wed, Jun 15, 2011 at 9:53 AM, Vlad Stoianovici < > [email protected]> wrote: > >> >> Dear list, >> I'm using a typical UHD USRP source (USRP2) --> Low-Pass filter --> GMSK >> Demod --> Packet Decoder --> File Sink receiver flow-graph in GnuRadio to >> receive the signal I'm transmitting with a mirrored transmitting flow. >> The problem is that the Packet Decoder (Output type - "byte"; Access Code >> - >> field left blank; Threshold -" -1") doesn't really do anything, the >> signal >> streams blocks there, and the file that the File Sink should create with >> the >> data from Packet Decoder is always empty. >> The rest of the flow-graph seems to be working properly, I can visualize >> the >> received signal, that seems to be the same as the transmitted one. >> > > Are you sure its not doing what its supposed to do? Look at the work() > function > in your packet decoder. If the input doesn't fit the requirement of the > algorithm to > produce the output then it won't produce anything at its output. Think of > it > this way. > Suppose the packet decoder block produces output items only when the input > is greater > than the threshold = T. If the input is constantly under T then there is > nothing produced. > > > If I take out the Packet Decoder, the file that results form the File Sink >> has a size larger than 0 bytes, which leads me to believe that the >> problem >> is with this block. >> Any ideas or similar problems? >> Thanks, >> >> Vlad. >> > > -- View this message in context: http://old.nabble.com/Packet-Decoder-block-malfunction-after-demodulation%21-tp31852171p31860105.html Sent from the GnuRadio mailing list archive at Nabble.com. _______________________________________________ Discuss-gnuradio mailing list [email protected] https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
