Hi Steve and all, In coming days I hope to catch up with your work on sfrsd. I haven't yet tested r5970 under crowded-band, HF-style conditions.
I did make a quick test on my group of single-signal 1000 files generated by SimJT, with S/N=-24 dB. The program ran well and was fast, but the results were only fair: 476/1000 decodes. Revision 5942 produced 837/1000 good decodes (and NO bad decodes) with ntrials=10000. Of course we can increase ntrials, though my decodes-vs-ntrials graph http://physics.princeton.edu/pulsar/K1JT/decodes_vs_ntrials3.pdf suggests that this is not the issue. Do you think we may need to use different erasure probabilities for HF and EME-like conditions? -- Joe On 10/11/2015 5:11 PM, Steven Franke wrote: > Hi Joe and all, > > This message summarizes my recent work on jt65 decoding in 1.6.1. > > I’ve added 3 new entries to the table summarizing JT-65a decoding results on > my batch of 333 20m .wav files. > > Program Good Bad Soft Decoder > -------------------------------------------------------------------------------------------------------- > 1. WSJT-X r5922 3125 0 574 BM+kvasd (18.4% kvasd) > 2. WSJT-X r5922 3123 2 572 BM+sfrsd (18.4% sfrsd, > ntrials=10000) > 3. WSJT-X r5922 2551 0 0 BM only > 4. WSJT-X r5955 2704 0 482 BM+sfrsd2 (17.8% sfrsd, > ntrials=5000) > 5. WSJT-X r5955 2222 0 BM only > 6. WSJT-X r5970' 2352 0 BM only (ntrials set equal > to 0, thresh0=2.5) > 7. WSJT-X r5970 2930 ? 579 BM+sfrsd2 (19.7% sfrsd, > thresh0=2.5, ntrials=2000) > 8. WSJT-X r5970’ 3013 ? ? BM+sfrsd2 (thresh0=1.5, > ntrials=2000) > > The r5970 version includes a number of tweaks: > - threshold is now set to 2.5, ntrials is 2000 > - a couple of fixes for out-of-bounds errors related to the switch to the > sync65 routing that I experienced on my data set > - new erasure probabilities for use with the simple “sf” symbol metrics > - simplification of the codeword acceptance criteria in sfrsd2 and extract > - all acceptance tests moved into sfrsd2. > > I did many runs (my notes from this weekend include 25 runs with various > tweaks and changes) and concluded that, for my data, I got better results > using matched sf symbol metrics and erasure probabilities — ymmv. > > While performance is significantly better in r5970 than it was in r5955, the > overall number of decodes is still less than what it was back in r5922. On > the other hand r5970 is running much faster than r5922 did, because r5922 > used ntrials=10000. > > Case 8 shows that we can obtain 83 more decodes by lowering the threshold to > 1.5, but execution time increases significantly because of the larger number > of spurious syncs. > > Also, comparison of cases 6 and 7 shows that the percentage of total decodes > obtained using sfrsd2 is almost 20% in r5970, and is higher than previously > seen with kvasd or sfrsd in r5922. > > Steve k9an > ------------------------------------------------------------------------------ > _______________________________________________ > wsjt-devel mailing list > wsjt-devel@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/wsjt-devel ------------------------------------------------------------------------------ _______________________________________________ wsjt-devel mailing list wsjt-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/wsjt-devel
