On 04/09/2013 02:14 PM, M. Ranganathan wrote: > This seems like a common scenario and it seems like it would make sense to > push the behaviour as low as possible in the stack. Is there a > configuration parameter for the USRP "device driver" that instructs the > driver to drop self routed signals? >
So it would be possible to mute the ADC samples when the device is transmitting. However, that might only be desirable in a couple of use cases, and there are probably a dozen ways to solve this from all the way down at the physical layer up the the MAC layer: * mute the RX ADC when transmitting (probably an FPGA mod) * tune RX and TX two different center frequencies * mute the samples going into the demodulator block when transmitting * use the issue_stream_command api to avoid receiving when transmitting * use a different preamble on the packets so you cant correlate yourself * use an identifier in the header of the packet to differentiate nodes I believe precog addresses this issue by using the last option. Your MAC layer has to be able to identify what a packet is and who it is destined to after all: https://github.com/jmalsbury/pre-cog/wiki -josh > > On Tue, Apr 9, 2013 at 2:50 PM, Marcus D. Leech <[email protected]> wrote: > >> ** >> >> Thanks Marcus for the explanation. Yes, we take care**** >> >> of attenuating the signal along the RF-cable.**** >> >> ** ** >> >> Can you explain bit more**** >> >> “So the best approach is to simply set a bit in your application for your >> RX chain to simply ignore the RX samples while you're transmitting”.**** >> >> ** ** >> >> can this be done in the python layer or do I have to touch the c++**** >> >> layer? I am using ofdm as the physical layer (ofdm.py etc.).**** >> >> ** ** >> >> Sorry, if all this sounds incoherent; I am still a newbee in this**** >> >> field.**** >> >> ** ** >> >> thanks and regards**** >> >> ** ** >> >> --Anirudh Sahoo**** >> >> Advanced Network Technology Div.**** >> >> National Institute of Standards and Technology (NIST)**** >> >> 100 Bureau Drive,**** >> >> Gaithersburg, MD - 20878**** >> >> Room – B230, bldg.- 222**** >> >> Phone- 301-975-4439**** >> >> Well, assuming you have TX thread and an RX thread, you can signal to the >> RX thread, via a shared variable, or some such, >> that TX is currently in progress, and to please ignore any samples for >> a while, or some such thing. >> >> I'll make the general comment that nobody can be really successful in SDR, >> if the 'S' part of it is a bit of a mystery to them. >> Real-world signal-processing solutions require things beyond the >> strictly-mathematical treatments of DSP you find in textbooks. >> In real systems, you need to implement algorithms that aren't >> strictly-mathematical in nature, and require some non-trivial >> understanding of familiar topics in CS and computer-programming >> concepts. >> >> >> >> >> -- >> Marcus Leech >> Principal Investigator >> Shirleys Bay Radio Astronomy Consortiumhttp://www.sbrac.org >> >> >> _______________________________________________ >> Discuss-gnuradio mailing list >> [email protected] >> https://lists.gnu.org/mailman/listinfo/discuss-gnuradio >> >> > > > > > _______________________________________________ > Discuss-gnuradio mailing list > [email protected] > https://lists.gnu.org/mailman/listinfo/discuss-gnuradio > _______________________________________________ Discuss-gnuradio mailing list [email protected] https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
