1 files changed, 19 insertions, 7 deletions
diff --git a/paper/safety-reset-paper.tex b/paper/safety-reset-paper.tex
index c9a54d9..2525b67 100644
--- a/paper/safety-reset-paper.tex
+++ b/paper/safety-reset-paper.tex
@@ -838,6 +838,13 @@ without triggering them to reset.
     to the smart meter in the middle through an adapter board. The top left contains a USB hub with debug interfaces to
     the reset microcontroller. The cables on the bottom left are the debug USB cable and the \SI{3.5}{\milli\meter}
     audio cable for the simulated mains voltage input.}
+    \Description{A photo of the safety reset prototype. Visible is a stand made from plywood to which a smart meter is
+    mounted in the middle. To one side of the smart meter a light switch and a socket are connected. To the other side,
+    an orange power cable exits towards the back of the stand. The smart meter is connected to a prototype circuit board
+    with colorful wires. The prototype circuit board is in turn connected to a microcontroller development board. The
+    development board is connected to a USB hub with both an SWD programming adapter and a USB to serial converter. A
+    usb cable from the USB hub as well as a 3.5 millimeter audio cable from the prototype circuit board are neatly
+    coiled up and hang down from the stand.}
     \label{fig_proto_pic}
 \end{figure}
 
@@ -864,13 +871,18 @@ the meter's display after boot-up.
     \centering
     \includegraphics[width=0.45\textwidth]{prototype_schema}
     \caption{The signal processing chain of our demonstrator.}
-    \Description{A photo of the safety reset prototype. Visible is a stand made from plywood to which a smart meter is
-    mounted in the middle. To one side of the smart meter a light switch and a socket are connected. To the other side,
-    an orange power cable exits towards the back of the stand. The smart meter is connected to a prototype circuit board
-    with colorful wires. The prototype circuit board is in turn connected to a microcontroller development board. The
-    development board is connected to a USB hub with both an SWD programming adapter and a USB to serial converter. A
-    usb cable from the USB hub as well as a 3.5 millimeter audio cable from the prototype circuit board are neatly
-    coiled up and hang down from the stand.}
+    \Description{A diagram showing the signal processing flow. The diagram shows a number of steps going from grid
+    voltage waveform to trigger decition. The diagram begins with the DMA-assisted ADC capture. At this point, the
+    signal is a clean analog sine wave. The next step is grid frequency estimation, after which the signal is a
+    noise-like ragged line. After grid frequency estimation follows DSSS demodulation, which itself is made up of three
+    steps. The first step of DSSS demodulation is convolution, which produces a small noise signal with a large peak
+    somewhere in the middle. The peak is roughly ten times the amplitude of the noise and has two prominent negative
+    sidelobes to the left and right. The following step, CWT peak contrast enhancement, clenas up this signal and
+    removes the side-lobes leaving only the positive peak sticking out of the background noise. The final step of DSSS
+    demodulation is maximum likelihood estimation, which produces a vector of n plus k discrete elements. After DSSS
+    demodulation, this vector is passed through Reed-Solomon error correction, which transforms it into a vector of now
+    only n discrete elements. This vector is then finally processed in the cryptographic trigger protocol, which
+    produces the final trigger decision.}
     \label{fig_demo_sig_schema}
 \end{figure}