I'm currently doing an internship at school and i'm working with USRP N210 and GNUradio. It's been a month since I began working with these 2 tools, so excuse me if I may sound noob, but I really need some help. I've been asked to start thinking about developing an UAT for civil aviation. I've read a ton of standards and papers concerning this new technology, so I won't relate it all over here, but the main thing about it is that it uses FSK mod/demod for the information to be transmitted and received.
I'm currently stuck on a problem that's been haunting me for the last 2 weeks and that's why i'm asking for your guidance. When I run the mod/demod on simulation(attached #1), everything works fine. I'm sending abcdefghijklmopqr
and on the receiving side i got the same thing. Now the problem is that when i'm trying to send it via the USRP with a cable between RX and TX(attached #2), i only get gibberish on the receiving side !
What have I done wrong ? I don't get why it's not working.