Hello (1) I mean "usrp.tune", use the instruction i can set my target frequency at 13.56MHz.
Now, I know you mean Usrp output I/Q samples. And you want to use one of them (I or Q sample). My answer is NO, because I/Q sample you can see it like SIN and COS signal. So need both I/Q to demodulate signal. (If I am wrong, please tell me.) The detail in book is very diffcult to me. I don't know how to explain. Maybe someone can help me to explain it. (2) Sorry for my misunderstand before. Use fft_sink, you can see usrp get the target frequency signal. for example, my target is 13.56MHz. When my RFID device near USRP, I will see a wavefrom raise in 13.56MHz. (3) In ISO/IEC 14443A PCD to PICC using ASK100%, PICC to PCD using different modulation (OOK). I just got draft spec. I need more study to understand the spec. (4) My question to RFID spec. Do you know, what is Pause_A? CJay Marco Bottino wrote: > Hello CJay, >> (1) > What do you mean with tune the target frequency? Isn't the carrier > always at > 13.56MHz? >> However, I don't understand the question "why USRP outputs I/Q samples?" >> I have to reading more knowledge about communication theory. > > I asked that because in my opinion I should not need any kind of phase > information because of the ASK modulation used that is an amplitude > modulation. > So I don't know if I have simply to throw away the Q samples or not... > >> >> (2) You want to plot in the time domain >> When I got RFID signal, I will do demodulation and get the information >> carried by the phase. I still trying. > > I'm sorry for my ignorance but which is the information carried by the > phase? > With "demodulation" what do you exactly mean? USRP isn't able to sample > directly at the RFID's frequency? > > Finally, reading the ISO standards it seems that is always used the ASK > modulation... isn't it? > > Thank you, > > Marco -- Posted via http://www.ruby-forum.com/. _______________________________________________ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
