Jim- > I'm working on a software-defined acoustic communications transceiver, > currently based on DSP-targeted code generated by MATLAB and Simulink. > I'm looking into options for converting the project to free software and > so far I have been reading about Scicos and GNURadio. As part of moving > to a free software platform, I would also transition the system from a > DSP target to a general purpose (PC) processor. > > I'd like to make the whole system real time capable (rather than > data-acq followed by post-processing) and I hope to get an idea from the > gnuradio list membership of what is possible on a general purpose > processor, and whether GNURadio is a good platform choice for my > application. For example, one difference from more typical SDR projects > is that we are doing direct quadrature sampling without a HW basebanding > front end. In the current design, the receiver does: > > - sampling at 4x the carrier (Fc @ 12kHz now, may go up -> 48ksps min, > maybe 96ksps in the future?) > - digital I-Q demodulation, decimation > - correlation to detect start-of-packet > - demodulate & decode packet of QPSK symbols (training & data bits) > using a digital PLL, decision feedback equalizer and viterbi decoder, > currently 200 training symbols & 600 data symbols > - a bit of MAC and application layer stuff (but this is lower processor > demand) > > Is this possible? Or perhaps trivial, compared to RF data rates? Does it > look like I'd need to write a bunch of new blocks if I moved to GNU > Radio? :) > > For comparison, the existing (floating-point) DSP implementation runs a > bit behind real time. It takes about 3 seconds to process a packet of > length ~0.7 second.
How many MFLOPS does your DSP solution currently require? You mention a floating-point DSP; is it the Texas Inst C6713? If so is it running 300 MHz / 1200 MFLOPS? -Jeff I would like to do better. The PC-compatible > hardware platform I had in mind is the Via PX10000 (for size/power > reasons); it seems fairly fast and has a nice built in audio codec with > a high sampling rate. > > http://www.engadget.com/2007/06/03/via-epia-px10000-pico-itx-motherboard-gets-reviewed/ > > I am fairly new to software-defined radio in general. Thanks in advance > for any suggestions. > > --Jim Morash > [EMAIL PROTECTED] _______________________________________________ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
