On Dec 4, 2007 2:00 PM, George Nychis <[EMAIL PROTECTED]> wrote: > I see, I want to go lower than the PHY layer really...
You can't go lower than the PHY layer. There's a reason it's the lowest on the stack. > Here's the thing, I don't want the solution to be dependent on the > physical layer. The goal is a development platform, and by choosing a > solution dependent on GMSK, I essentially lock all MAC development in to > using GMSK. Is there a solution independent of the PHY layer? I > suppose I'm still not sure :) You can use a matched filter for this, but a generalized matched filter uses multipliers. If you limited yourself to GMSK, PSK, or QAM you can get away with sign manipulations. OFDM would require different processing in general. > If some mechanism could be built in the FPGA that was highly > reconfigurable, that would be fine... but it seems to be boiling down to > different techniques per-modulation. Not really an option for the USRP as it currently is due to the lack of hardware multipliers. Maybe more of an option for the USRP2. On a side note, you should not feel bad about making something that considers a trade-off in the realm of software defined radio. You are giving up (slight) PHY layer flexibility for much improved latency. We're still using an antenna. We're still using a super heterodyne receiver. Some things just can't be software and are limitations - working around them is fine. Brian _______________________________________________ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
