From adc00a39baff866a3b68b52ffc55a4aae71e61c4 Mon Sep 17 00:00:00 2001
From: Nao Pross <np@0hm.ch>
Date: Sun, 31 Oct 2021 00:20:51 +0200
Subject: Fix math error in QAM, improve QAM modulator diagram, rename (wrong)
QPSK to PSK
---
doc/thesis/figures/tikz/psk-constellation.tex | 23 ++++++++++
doc/thesis/figures/tikz/qam-modulator.tex | 58 +++++++++++++++++++++++---
doc/thesis/figures/tikz/qpsk-constellation.tex | 23 ----------
3 files changed, 76 insertions(+), 28 deletions(-)
create mode 100644 doc/thesis/figures/tikz/psk-constellation.tex
delete mode 100644 doc/thesis/figures/tikz/qpsk-constellation.tex
(limited to 'doc/thesis/figures/tikz')
diff --git a/doc/thesis/figures/tikz/psk-constellation.tex b/doc/thesis/figures/tikz/psk-constellation.tex
new file mode 100644
index 0000000..d927b19
--- /dev/null
+++ b/doc/thesis/figures/tikz/psk-constellation.tex
@@ -0,0 +1,23 @@
+% vim: set ts=2 sw=2 noet:
+\begin{tikzpicture}[
+ axis/.style = {
+ thick, -latex, black,
+ },
+ star/.style = {
+ draw = black, thick, fill = red!50,
+ circle, outer sep = 1mm, inner sep = 0,
+ minimum size = 1.5mm,
+ },
+ ]
+ \draw[axis] (-25mm,0) to (25mm,0) node[right] {\(\phi_i\)};
+ \draw[axis] (0,-25mm) to (0,25mm) node[above] {\(\phi_q\)};
+
+ \draw[lightgray, densely dotted, thick] (0,0) circle (15mm);
+ \foreach \a in {0,1,...,8}{
+ \node[star] (s\a) at ({360/8*(.5 + \a)}:15mm) {};
+ }
+
+ \foreach \i/\l in {0/000,1/001,2/011,3/010,4/110,5/111,6/101,7/100}{
+ \node[lightgray] at ($(s\i) + ({360/8*(.5 + \i)}:5mm)$) {\texttt{\l}};
+ }
+\end{tikzpicture}
diff --git a/doc/thesis/figures/tikz/qam-modulator.tex b/doc/thesis/figures/tikz/qam-modulator.tex
index 59d989f..a55ff29 100644
--- a/doc/thesis/figures/tikz/qam-modulator.tex
+++ b/doc/thesis/figures/tikz/qam-modulator.tex
@@ -57,7 +57,7 @@
\draw (B2Lq.east) -- (Mq.west);
\draw (Mq.east) -| (SUM.south);
- \draw (SUM) -- (S);
+ \draw (SUM.east) -- (S);
\draw (OSC.east) -| (Mi.south);
\draw (OSC.west) -- (H.east);
@@ -77,13 +77,61 @@
\node[above left] at (si) {\(s_i(t)\)};
\node[below left] at (sq) {\(s_q(t)\)};
+ % Draw digital signals
+ \begin{scope}[font = \ttfamily\footnotesize, text = blue!70!white]
+ \node[above = 1mm of M, xshift = 2mm] {\(\ldots 1100101\)};
+ \node[above = 7mm of vmi, xshift = 3mm]
+ {\(\overbracket[.8pt]{\,11\ldots 00\,}^{\sqrt{M} \text{ bits}}\)};
+ \end{scope}
+
+ % Draw analog waveform
+ \begin{scope}[font = \ttfamily\tiny]
+ \coordinate (O) at ($(mi)+(-2mm,10.5mm)$);
+
+ \node[left, red!70!white, anchor = east, text width = 8mm, align = right]
+ at ($(O) + (-2mm,0)$) {\(2^{\sqrt{M}}\) levels};
+
+ \foreach \y in {-3mm,0,3mm} {
+ \draw[gray, densely dotted] (O) ++(-2mm,\y) -- ++(22mm,0);
+ }
+
+ \draw[thick, draw = red!70!white] (O)
+ -- ++(3mm,0) -- ++(0,-3mm) -- ++(3mm,0) -- ++(0,6mm)
+ -- ++(3mm,0) -- ++(0,-3mm) -- ++(3mm,0) -- ++(0,-3mm)
+ -- ++(3mm,0) -- ++(0,3mm) -- ++(3mm,0);
+ \end{scope}
+
+ % Draw constellation diagram
+ \begin{scope}
+ \coordinate (O) at ($(S)+(-7mm,8mm)$);
+ \draw[gray, -latex] (O) ++(-2mm,0) -- ++(12mm,0) node[right] {\tiny \(\phi_i\)};
+ \draw[gray, -latex] (O) ++(0,-2mm) -- ++(0,12mm) node[above] {\tiny \(\phi_q\)};
+
+ \node[
+ circle, thick,
+ minimum size = 3pt,
+ inner sep = 0, outer sep = .8pt,
+ draw = gray, fill = red!50!white
+ ] (P) at ($(O)+(5mm, 4mm)$) {};
+
+ \node[gray, above right] at (P) {\tiny \(s\)};
+
+ \draw[gray, densely dotted]
+ (P) -- (P |- O)
+ (P) -- (P -| O);
+ \end{scope}
+
+
+ % Background elements
\begin{pgfonlayer}{background}
\fill[left color = white, right color = blue!20, draw = white]
- ($(B2Li.north) + (0,1)$) coordinate (D) rectangle ($(B2Lq.south) - (3,1)$);
+ ($(B2Li.north) + (0,1.1)$) coordinate (D) rectangle ($(B2Lq.south) - (3,1)$);
\fill[right color = white, left color = red!20, draw = white]
- ($(B2Li.north) + (0,1)$) coordinate (A) rectangle ($(B2Lq.south) + (9,-1)$);
+ ($(B2Li.north) + (0,1.1)$) coordinate (A) rectangle ($(B2Lq.south) + (9,-1)$);
- \node[blue!50, anchor = south east, font = \ttfamily\bfseries, xshift = -4mm] at (D) {\bfseries\ttfamily Digital bits};
- \node[red!50, anchor = south west, font = \bfseries\ttfamily, xshift = 4mm] at (A) {Analog waveform};
+ \node[blue!50, anchor = south east, font = \ttfamily\bfseries, xshift = -4mm]
+ at (D) {\bfseries\ttfamily Digital bits};
+ \node[red!50, anchor = south west, font = \bfseries\ttfamily, xshift = 4mm]
+ at (A) {Analog waveform};
\end{pgfonlayer}
\end{circuitikz}
diff --git a/doc/thesis/figures/tikz/qpsk-constellation.tex b/doc/thesis/figures/tikz/qpsk-constellation.tex
deleted file mode 100644
index d927b19..0000000
--- a/doc/thesis/figures/tikz/qpsk-constellation.tex
+++ /dev/null
@@ -1,23 +0,0 @@
-% vim: set ts=2 sw=2 noet:
-\begin{tikzpicture}[
- axis/.style = {
- thick, -latex, black,
- },
- star/.style = {
- draw = black, thick, fill = red!50,
- circle, outer sep = 1mm, inner sep = 0,
- minimum size = 1.5mm,
- },
- ]
- \draw[axis] (-25mm,0) to (25mm,0) node[right] {\(\phi_i\)};
- \draw[axis] (0,-25mm) to (0,25mm) node[above] {\(\phi_q\)};
-
- \draw[lightgray, densely dotted, thick] (0,0) circle (15mm);
- \foreach \a in {0,1,...,8}{
- \node[star] (s\a) at ({360/8*(.5 + \a)}:15mm) {};
- }
-
- \foreach \i/\l in {0/000,1/001,2/011,3/010,4/110,5/111,6/101,7/100}{
- \node[lightgray] at ($(s\i) + ({360/8*(.5 + \i)}:5mm)$) {\texttt{\l}};
- }
-\end{tikzpicture}
--
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