I looked at the spectrums of both sides and the RX side looks to be inundated with a lot of noise. I'm not sure if its my environment or my USRPs, but I really expected to see some resemblance of a signal. I am posting links to screencaps of the TX and RX sides.
http://imgur.com/GBTHw8T- TX http://imgur.com/DBy8gqs - RX Logan Washbourne Electrical Engineering Graduate Student (Electromagnetics) On Mon, Oct 26, 2015 at 1:31 PM, Marcus Müller <marcus.muel...@ettus.com> wrote: > Can you compare the TX spectrum with the RX spectrum? Maybe it'd > worthwhile to first look at at e.g. 500kHz of RX spectrum to see whether, > due to frequency offset, some of the wanted signal simply gets cut off; > admittedly, with 2S/sym that's not too likely... > > Best regards, > Marcus > > > On 26.10.2015 19:16, Washbourne, Logan wrote: > > I am using 250k! > > > > Logan Washbourne > Electrical Engineering Graduate Student > (Electromagnetics) > > > On Mon, Oct 26, 2015 at 1:05 PM, Marcus Müller <marcus.muel...@ettus.com> > wrote: > >> Hello! >> what's the sampling rate you're using? >> >> Best regards, >> Marcus >> >> >> On 26.10.2015 18:38, Washbourne, Logan wrote: >> >> Hello all, >> >> I'm trying to take a step back from my previous postings and try a simple >> approach to try and understand working with over the air communications >> with the USRPs. Let me know if it would be better to post this in the >> USRPs-Users list. >> >> I'm trying to have a simple TX and simple RX side so I can eliminate and >> unnecessary complications. >> >> The TX side has the following flowgraph: Vector >> Source(preamble+data)->DPSK Mod(DBPSK,2samples/symbol)-> Multiply >> Const(.707) -> UHD:USRP SINK(2.448GHz center freq, 10dB default gain) >> >> RX Side: UHD:USRP Source(2.448GHz center freq, 10dB gain default) -> DPSK >> DEMOD(DBPSK, 2 samples/ symbol, rest default values) - > file sink >> >> I'm checking the progress of the communication by looking at a >> constellation plot that is connected directly to the USRP SOURCE block on >> the receiver side. I'm getting a very elliptical shape, more spread out in >> the horizontal direction but not by much. I'm also looking at the bits from >> the receiver side in matlab and my preamble is not showing up. >> >> These were the same problems I had when trying to use a correlated system >> for OTA communications. I feel like I'm missing something really simple. >> >> Does anyone know of a simple TX, RX grc setup that I can use to test my >> USRPs? >> >> Again, I really appreciate the help you guys give. >> >> Logan Washbourne >> Electrical Engineering Graduate Student >> (Electromagnetics) >> >> >> >> _______________________________________________ >> Discuss-gnuradio mailing >> listDiscuss-gnuradio@gnu.orghttps://lists.gnu.org/mailman/listinfo/discuss-gnuradio >> >> >> >> _______________________________________________ >> Discuss-gnuradio mailing list >> Discuss-gnuradio@gnu.org >> https://lists.gnu.org/mailman/listinfo/discuss-gnuradio >> >> > > > _______________________________________________ > Discuss-gnuradio mailing > listDiscuss-gnuradio@gnu.orghttps://lists.gnu.org/mailman/listinfo/discuss-gnuradio > > > > _______________________________________________ > Discuss-gnuradio mailing list > Discuss-gnuradio@gnu.org > https://lists.gnu.org/mailman/listinfo/discuss-gnuradio > >
_______________________________________________ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
