Hi all, I will implement a ZigBee transceiver on Gnuradio using channels in the 2.4GHz ISM band. I studied a bit the IEEE standart and I could observe that ZigBee uses DSSS channel encoding with 32 chips long random noise sequences and an offset QPSK modulation scheme. The offset between In-phase and quadrature streams is a half symbol duration. Does anybody have an idea how to build a phase detector and decision device for this modulation in Gnuradio? What's about the costas loop for QPSK detection? Is this loop able to trigger the offset fast enough or should I build two phase detection loops, one for each stream (I & Q). After having the two streams what could be the best way to achieve symbol recovery? And , as last question for the moment, in transmission mode how can I build a delay for the offset needed? DSSS is not a big deal and I think that I will write a block with simple mapping tables.
I am still designing the application and some tips would be very precious to start implementation by the right way. I appreciate any advise or tip and I'd like to thank all of you in advance. Luis _______________________________________________ Discuss-gnuradio mailing list [email protected] http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
