Hello, I've been looking into how usrp_spectrum_sense works and I have a question about my understanding of how it works.
The basic idea is that is that you tune, take FFT(s?), then retune, etc. This is done with the fft block and the stats block. My questions are: 1) What is input_items conceptually? I think it is a vector of pointers to different fft sweeps, but I could be wrong. 2) So, is this code taking several FFTs then the for loop and accrue_stats finds the maximum magnitude of each of the FFT bins. Is that right? 3) Could I change dwell_time to change the number of FFTs that are taken? 4) If I wanted to do some averaging (instead of find the max magnitude) could I would have to edit accrue_stats Here's all the relevant code from gnuradio-core/src/lib/general/gr_bin_statistics_f.cc const float *input = (const float *) input_items[0]; size_t vlen = d_max.size(); int n = 0; int t; while (n < noutput_items){ switch (d_state) ... case ST_DWELL_DELAY: t = std::min(noutput_items - n, int(d_delay)); for (int i = 0; i < t; i++){ accrue_stats(&input[n * vlen]); n++; } d_delay -= t; assert(d_delay >= 0); if (d_delay == 0){ leave_dwell_delay(); enter_tune_delay(); } break; ... void gr_bin_statistics_f::accrue_stats(const float *input) { for (size_t i = 0; i < vlen(); i++){ d_max[i] = std::max(d_max[i], input[i]); // compute per bin maxima } } Thanks for any help, Devin _______________________________________________ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio