AW: [Discuss-gnuradio] Why is Barker Spreading difficult to usrp?
Hello! I´m really new to gnu-radio. I installed the 3.0.4 version on my Ubuntu system finally and now I need some ideas, here is what I want to do: I want to use the USRP to sniff everything going on between 2 WLAN-PCMCIA Laptops on 2,4GH. How do I do that..? Does GNU Radio give me any tools making it possible to visualize this in any way? Thx! Tomek ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
Re: [Discuss-gnuradio] Why is Barker Spreading difficult to usrp?
DiX <[EMAIL PROTECTED]> writes: >With BBN codes and FLEX2400 d'borads, now I can received 802.11b > packets from standard wireless cards, and communicate between two USRPs with > barker spreading off. These make me really excited :) That's good to hear - that matches where we got to. >However, I failed trying to send any packet from USRP to PC. I > believe it is because the barker spreading of thej tx path was not working > well and PC could not interpret the packets correctly. I also sent packets > between USRP with barker on. That did not work too. I am not sure if we ever thought that we had the barker transmit working. >It seems barker demodulator works but modulator does not. Why is the > barker spreading difficult for usrp? Is it because the 1MSps symbol rate is > too tough for the USRP board? ( USRP is not that fast to deal with 1 > million 11-bit batter sequence?) It's because the bandwidth of the signal from 1 Msample/s times 11 chip/symbol is 11 Mchip/s. I think we used 8-bit i/q and 8 Msample/s to get 16 MB/s across the USB. For the barker receiver, the code computes pre-distorted waveforms of the barker code. I don't know that the transmitter does, but really I think it just has to hope for the best in terms of the receiver receiving a distorted signal. You may be able to up the rate to 32 MB/s (16 Msample/sec) and tx may work better. Or, you could implement the barker code in the fpga. The BBN code is assigned to FSF, so you are welcome to integrate it into GNU Radio proper. ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
[Discuss-gnuradio] Why is Barker Spreading difficult to usrp?
Hi guys, With BBN codes and FLEX2400 d'borads, now I can received 802.11b packets from standard wireless cards, and communicate between two USRPs with barker spreading off. These make me really excited :) However, I failed trying to send any packet from USRP to PC. I believe it is because the barker spreading of the tx path was not working well and PC could not interpret the packets correctly. I also sent packets between USRP with barker on. That did not work too. It seems barker demodulator works but modulator does not. Why is the barker spreading difficult for usrp? Is it because the 1MSps symbol rate is too tough for the USRP board? ( USRP is not that fast to deal with 1 million 11-bit batter sequence?) Best, Dix -- View this message in context: http://www.nabble.com/Why-is-Barker-Spreading-difficult-to-usrp--tf4647456.html#a13275970 Sent from the GnuRadio mailing list archive at Nabble.com. ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
