diff --git a/ex05/kn05.pdf b/ex05/kn05.pdf index e38add0..887842d 100644 --- a/ex05/kn05.pdf +++ b/ex05/kn05.pdf Binary files differ diff --git a/ex05/kn05.tex b/ex05/kn05.tex index 8f59ae8..79a4e56 100644 --- a/ex05/kn05.tex +++ b/ex05/kn05.tex @@ -113,7 +113,10 @@ 549 ~kHz & 549000 ~Hz & 546.45 ~m & \text{Low Frequency LF} \end{array} $ -\end{center} \vspace{1cm} + \begin{corr} + Anwendung fehlt + \end{corr} +\end{center} \pagebreak \Aufgabe{Frequency-Division Multiplexing (FDM)}{6+6+6+6}\\ The available analogue satellite channel with bandwidth $B_{STA} = 4MHz$ is divided into the required $5$ channels, of which each has now $4MHz / 5 = 0.8MHz$ for transferring $N = 6Mbit/s$. Each digital channel is @@ -121,14 +124,19 @@ is demultiplexed and again demodulated with QAM. This leads to 5 output channel with the original 6Mbit/s. \begin{enumerate} \item The required bandwidth for each channel is $B_{QAM} = (1 + d) \cdot S$, with $d = 0$ and $S = 0.8MHz$ this leads to - $B_{QAM} = 0.8MHz$. + $B_{QAM} = 0.8MHz$.\begin{corr} + B=B, not S + \end{corr} \item The Nyquist theorem states, that the maximum bit rate $R_{max}$ is given as $R_{max} = 2 \cdot \log{2}{L}$. Since $\log{2}{L}$ is the number of bits per Baud, the maximum Baud per second $Bd_{max}$ is: \begin{align*} Bd_{max} = 2 \cdot B_{channel} = 2 \cdot 0.8 MHz = 1.6 MHz \end{align*} - \item The required number of bits per symbol is $r = \frac{N}{S} = \frac{\enot{6}{6}bit/s}{\enot{0.8}{6}1/s} = 7.5 Bits$ - \item The required number of symbols for QAM is $L = 2^{\lceil r\rceil} = 2^{\lceil 7.5\rceil}=2^8 = 256$. + \begin{corr} + $S=0.8MBd$, since $B=(1+0)S$ + \end{corr} + \item The required number of bits per symbol is $r = \frac{N}{S} = \frac{\enot{6}{6}bit/s}{\enot{0.8}{6}1/s} = 7.5 Bits$\ok + \item The required number of symbols for QAM is $L = 2^{\lceil r\rceil} = 2^{\lceil 7.5\rceil}=2^8 = 256$.\ok \end{enumerate} \vspace{1cm} \Aufgabe{Analog and Digital Hierarchy}{14+14} \begin{enumerate} @@ -138,6 +146,14 @@ \textbf{analog} signals are multiplexed into a single link using \textbf{Frequency Division Multiplexing}. In digital hierarchy, a bunch of \textbf{digital} signals are multiplexed into a single link using \textbf{Time Division Multiplexing}. It is also to be noted, that the digital signals can carry analog information (e.g. speech signals). + \begin{corr} + \begin{itemize} + \item FDM $\leftrightarrow$ TDM + \item digital vs. analog + \item Stufenaufbau etwas verschieden + \item Hierachie + \end{itemize} + \end{corr} \item All three stand for the lowest level of their hierarchy. \begin{enumerate} \item STS-1, OC-1\\ @@ -146,6 +162,9 @@ \item DS-0\\ has 64kBit/s (PCM-modulated human voice) and was used by phone companies. It is a single voice channel and was used to transport one phone call.\\ DS is used for digital signals. + \item \begin{corr} + Bitraten(nicht gefragt), Stufen fehlen + \end{corr} \end{enumerate} \end{enumerate} \end{document}