Hello, I am a student and I am doing my thesis project on the RFID protocols. At the present time, with the USRP, I am trying to catch the signal between a reader and a tag RFID. As reader I am using an OpendPCD (using the firmware for the Mifare Classic protocol) and as card a Mifare Classic Card.
Because of I am a very beginner of USRP and all the rest, I am using the programs usrp_fft.py and usrp_oscope.py and the usrp_rx_cfile.py program with another program called Baudline to analyse the spectrum. My problem is that I can easily see in the frequency domain, using usrp_fft, the carrier at 13.561Mhz, but not the subcarrier that should be a 847KHz modulation of the carrier (probably covered by noise) even if I try to use a baseRX daughterboard instead of the LFRX. Moreover, in the time domain (with the usrp_oscope), I cannot recognize anything interesting. As it isn't enough, with the usrp_rx_cfile and the program baudline I cannot recognize neither the carrier: my opinion is that it is caused by a wrongly interpretation of the bit-length of the samples (and for this I should need a confirmation that the output samples are 16 bit-length). That program supports these formats: alaw ulaw s8 u8 le16 be16 le32f be32f. Does anybody know wich is the format I should use? Probably I'm using wrongly the hardware and the software I have... Could somebody suggest me a solution? Any kind of help will be absolutely well appreciated! thank you, Marco _______________________________________________ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
