diff --git a/lib/ftrsd/ftrsd_paper/fig_subtracted.tiff b/lib/ftrsd/ftrsd_paper/fig_subtracted.tiff new file mode 100644 index 000000000..b6f0f2fad Binary files /dev/null and b/lib/ftrsd/ftrsd_paper/fig_subtracted.tiff differ diff --git a/lib/ftrsd/ftrsd_paper/ftrsd.lyx b/lib/ftrsd/ftrsd_paper/ftrsd.lyx index 1166e36dc..865705326 100644 --- a/lib/ftrsd/ftrsd_paper/ftrsd.lyx +++ b/lib/ftrsd/ftrsd_paper/ftrsd.lyx @@ -2239,172 +2239,6 @@ MAP65 \emph default . -\end_layout - -\begin_layout Standard -Mention two-pass decoding - could use Fig -\begin_inset CommandInset ref -LatexCommand ref -reference "fig:spectrogram" - -\end_inset - - as a case study. - The table below is for the data shown in Fig -\begin_inset CommandInset ref -LatexCommand ref -reference "fig:spectrogram" - -\end_inset - -. - Maybe less confusing if the third row was deleted. -\begin_inset Float table -wide false -sideways false -status open - -\begin_layout Plain Layout -\align center -\begin_inset Tabular - - - - - - -\begin_inset Text - -\begin_layout Plain Layout -Case -\end_layout - -\end_inset - - -\begin_inset Text - -\begin_layout Plain Layout -# decodes -\end_layout - -\end_inset - - - - -\begin_inset Text - -\begin_layout Plain Layout -one-pass, BM -\end_layout - -\end_inset - - -\begin_inset Text - -\begin_layout Plain Layout -9 -\end_layout - -\end_inset - - - - -\begin_inset Text - -\begin_layout Plain Layout -one-pass, FT -\end_layout - -\end_inset - - -\begin_inset Text - -\begin_layout Plain Layout -12 -\end_layout - -\end_inset - - - - -\begin_inset Text - -\begin_layout Plain Layout -two-pass, BM -\end_layout - -\end_inset - - -\begin_inset Text - -\begin_layout Plain Layout -12 -\end_layout - -\end_inset - - - - -\begin_inset Text - -\begin_layout Plain Layout -two-pass, FT -\end_layout - -\end_inset - - -\begin_inset Text - -\begin_layout Plain Layout -21 -\end_layout - -\end_inset - - - - -\end_inset - - -\end_layout - -\begin_layout Plain Layout -\begin_inset Caption Standard - -\begin_layout Plain Layout -The effect of soft-symbol decoding combined with signal subtraction on the - data shown in Figure -\begin_inset CommandInset ref -LatexCommand ref -reference "fig:spectrogram" - -\end_inset - -. -\end_layout - -\end_inset - - -\end_layout - -\begin_layout Plain Layout - -\end_layout - -\end_inset - - \end_layout \begin_layout Subsubsection* @@ -2437,20 +2271,22 @@ moonbounce reflection paths at HF. Use on HF was not originally an intended application for the mode, but at present HF use accounts for the largest number of 2-way contacts. - Figure + +\end_layout + +\begin_layout Standard +Figure \begin_inset CommandInset ref LatexCommand ref reference "fig:spectrogram" \end_inset - is a spectrogram with frequency in Hz on the horizontal axis showing JT65 - activity during a one-minute time-segment (JT65 transmissions start at + (top) shows JT65 activity in a one-minute time-segment on the 20m amateur + band during crowded daytime band conditions (JT65 transmissions start at the beginning of a minute and last for approximately 47 s). - The data was collected in the 20m amateur band during daytime under crowded - band conditions. With some straightforward signal processing to demodulate the signals and - produce soft-symbol data for the FT decoder it is possible to extract and + produce soft-symbol data for the FT decoder we are able to extract and decode 21 messages from the data summarized in Figure 5. This is achieved with a relatively small timeout parameter \begin_inset Formula $T=1000$ @@ -2459,9 +2295,23 @@ reference "fig:spectrogram" and in spite of the fact that the 200 Hz-wide 65-FSK (sync plut 64-FSK) signals overlap, with as many as 4 signals superposed in some parts of the spectrum. + To achieve these results we use two successive sweeps over the spectrum. + The strongest signals are sequentially decoded and then subtracted from + the spectrum on the first pass. + Figure +\begin_inset CommandInset ref +LatexCommand ref +reference "fig:spectrogram" + +\end_inset + + (bottom) shows the spectrogram after subtracting 12 signals that were decoded + in the first pass. + Another 9 signals are decoded from the data shown in the bottom figure + on the second pass. Using exactly the same pre-processing, but without soft-symbol information - the errors-only BM decoder is able to decode only 12 messages. - + the errors-only BM decoder is able to decode only 12 messages in two passes + over the data. \end_layout \begin_layout Standard @@ -2481,6 +2331,18 @@ status open \end_inset +\end_layout + +\begin_layout Plain Layout +\begin_inset Graphics + filename fig_subtracted.tiff + width 6.5in + BoundingBox 0bp 0bp 1126bp 202bp + clip + +\end_inset + + \end_layout \begin_layout Plain Layout @@ -2493,10 +2355,10 @@ name "fig:spectrogram" \end_inset -A spectrogram showing one minute of data collected under crowded band conditions - on 20m during daytime hours. - WSJT-X extracted 21 JT65 messages in approximately the same bandwidth required - for a single SSB signal. +(top) A spectrogram showing one minute of data collected under crowded band + conditions on 20m during daytime hours. + (bottom) The spectrogram after the subtracting all signals successfully + decoded on the first pass. \end_layout