From 7d6fd8bebc494d02d9ab3963626cfd421f4acc63 Mon Sep 17 00:00:00 2001
From: sara <sara.halter@gmx.ch>
Date: Tue, 19 Oct 2021 17:18:54 +0200
Subject: Theory mit PSK und QPSK angefangen.

---
 doc/thesis/chapters/theory.tex | 23 +++++++++++++++++++++--
 1 file changed, 21 insertions(+), 2 deletions(-)

(limited to 'doc/thesis/chapters/theory.tex')

diff --git a/doc/thesis/chapters/theory.tex b/doc/thesis/chapters/theory.tex
index 343a30a..b930a19 100644
--- a/doc/thesis/chapters/theory.tex
+++ b/doc/thesis/chapters/theory.tex
@@ -5,10 +5,10 @@
 \section{Review of modulation schemes}
 
 \begin{figure}
-	\centering
+	\centering	
 	\input{figures/tikz/overview}
 	\caption{
-		Block diagram for a general wireless communication system with annotated signal names.
+		Block diagram for a general wireless communicatiSon system with annotated signal names.
 		Frequency domain representations of signals use the uppercase symbol of their respective time domain name.
 		\label{fig:notation}
 	}
@@ -34,6 +34,25 @@ Where \(\mu > 0\) is the so called modulation factor, that can be adjusted to av
 
 Quadrature amplitude modulation is a family of modern digital modulation methods, that use an analog carrier signal. The simple yet effective idea behind QAM is to encode extra information into an orthogonal carrier signal, thus increasing the number of bits sent per unit of time.
 
+\subsection{Phase Shift Keying (PSK)}
+
+PSK \cite{Meyer2011} is a popular modulation type for data transmission. With a bipolar binary signal, the amplitude remains constant and only the phase will be changed with phase jumps of 180 degrees, which can be seen as a multiplication of the carrier signal with $\pm$ 1. That is alow known as binary phase shift keying.
+\includegraphics[width=5cm]{./image/BPSK2.png}
+%TODO: Better Image
+%https://sites.google.com/site/billmahroukelec675/bipolar-phase-shift-keying
+
+\subsection{Quadrature Phase Shift Keying (QPSK)}
+
+Two bits are modulated at ones with the same bandwidth as a 2-PSK so more informations are transmitted at the same time. \cite{Meyer2011}
+%TODO: Image Signal Raum 
+Most times there is noise and the points on the constellation diagram become a surface. 
+If the surfaces overlap there will be a problem with decoding. 
+
+
+
+
+
+
 \section{Fading}
 
 \subsection{Geometric Model}
-- 
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