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Diffstat (limited to 'chapter06/content_ch06.tex')
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diff --git a/chapter06/content_ch06.tex b/chapter06/content_ch06.tex index 1a90ab4..03da595 100644 --- a/chapter06/content_ch06.tex +++ b/chapter06/content_ch06.tex @@ -8,7 +8,7 @@ % Please find the full copy of the licence at: % https://creativecommons.org/licenses/by-sa/4.0/legalcode -\chapter{Digital Signal Processing and Spread Spectrum} +\chapter{Digital Signal Processing} \begin{refsection} @@ -259,8 +259,6 @@ A stable filter has always a value-limited impulse response (\ac{BIBO} stable). \acs{IIR} filter must be always checked for stability. \end{fact} -\todo{examples} - \subsection{Finite Impulse Response Filters} A digital filter without the feed-back path will not have any problems with stability. @@ -826,7 +824,7 @@ or in the linear scale (\si{mW}): The quantization noise power is distributed equally over the frequency axis between $[-\frac{1}{2 T_{S,i}}, \frac{1}{2 T_{S,i}}]$, which is the band limit for the sampled input signal. The \index{noise bandwidth} \textbf{noise bandwidth} is therefore $\Delta f_{S,i} = \frac{1}{T_{S,i}}$. The quantization noise floor $S_{N,i}$, which is a \ac{PSD} (\si{mW/Hz}), is: \begin{equation} \begin{split} - S_{N,i} = \frac{P_{N,i}}{\Delta f_{S,i}} \\ + S_{N,i} &= \frac{P_{N,i}}{\Delta f_{S,i}} \\ &= \frac{P_{N,i}}{\frac{1}{T_{S,i}}} \\ &= P_{N,i} T_{S,i} \end{split} @@ -1372,74 +1370,7 @@ $\underline{E}[k]$ and $\underline{O}[k]$ need to be calculated one and can be r The Cooley-Tukey \acs{FFT} algorithm can be used to calculate the \ac{IFFT}, too. -\section{Spread Spectrum} - -\begin{figure}[H] - \centering - \begin{tikzpicture} - \begin{axis}[ - height={0.15\textheight}, - width=0.8\linewidth, - scale only axis, - xlabel={$\omega$}, - ylabel={$|\mathrm{S}_{XX}|$}, - %grid style={line width=.6pt, color=lightgray}, - %grid=both, - grid=none, - legend pos=north east, - axis y line=middle, - axis x line=middle, - every axis x label/.style={ - at={(ticklabel* cs:1.05)}, - anchor=north, - }, - every axis y label/.style={ - at={(ticklabel* cs:1.05)}, - anchor=east, - }, - xmin=0, - xmax=10.5, - ymin=0, - ymax=1.2, - xtick={0}, - xticklabels={0}, - ytick={0}, - axis x discontinuity=parallel, - ] - \addplot[blue, smooth] coordinates {(4.6,0) (4.7,0.02) (4.8,0.2) (4.9,0.71) (5,1) (5.1,0.71) (5.2,0.2) (5.3,0.02) (5.4,0)}; - \addlegendentry{Narrow-band signal}; - \addplot[red, smooth] coordinates {(2,0) (2.5,0.01) (3,0.05) (5,0.05) (7,0.05) (7.5,0.01) (8,0)}; - \addlegendentry{Spread spectrum signal}; - \end{axis} - \end{tikzpicture} - \caption[PSD of a narrow-band and spread spectrum signal]{\acs{PSD} of a narrow-band and spread spectrum signal. Both signals carry the same information and have the equal power. The narrow-band signal concentrates the whole signal power in a narrow frequency band. In contrast, the spread spectrum signal distributes the signal power over a wide frequency band.} -\end{figure} - -\todo{Purpose: Noise immunity} - -\todo{Noise like} - -\todo{Purpose: Immunity against narrowband disturbances} - -\todo{Purpose: Coexistence with other services, multiple access} - -\todo{Purpose: Plausible deniability} - -\todo{Purpose: Encryption, confidentiality} - -\subsection{Direct-Sequence Spread Spectrum} - -\todo{pseudorandom number} - -\todo{Processing Gain} - -\subsection{Frequency-Hopping Spread Spectrum} - -\subsection{Time-Hopping Spread Spectrum} - -\section{Multi-carrier Modulation} - -\todo{OFDM} +\nocite{rao2018} \phantomsection \addcontentsline{toc}{section}{References} |