# Changeset 9406

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06/10/09 17:13:12 (5 years ago)
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• ## ossiedev/branches/hvolos/docs/ChannelLab/ChannelLab.tex

r9405 r9406
6565
6666\section{Version}
67 This lab is for use with OSSIE version 0.7.x and the OSSIE Eclipse Feature (OEF), running on a
68 computer or VMware image that uses Fedora Core 7 or Ubuntu 8.04. The TxDemo,
69 Channel and RxDemo components are required.
67This lab is for use with OSSIE version 0.7.x, the OSSIE Eclipse Feature (OEF), and ALF running on a computer or VMware image that uses Fedora Core 7 or Ubuntu 8.04. The TxDemo, Channel and RxDemo components are required.
7068
7169\section{Procedure}

7977\subsection{Getting Started}
8078\subsection{Building the waveform}
79Using OEF build the ChannelEval waveform with the structure shown in \osref{waveformOEF}. In addition, \osref{blockdiagram} provides an alternative view of the waveform. Only the Channel component has configurable properties, set those properties according to \osref{wfmproperties}
8180\osfig{waveformOEF}{OEF Waveform Structure}
8281\osfig{blockdiagram}{Block Diagram}
8382\osfig{wfmproperties}{Initial Channel Component Properties}
8483\subsection{Theory}
85 SNR Estimation
84The TxDemo transmits QPSK symbols with energy $7000^2+7000^2=98000000$ (both I and Q components have an amplitude of 7000).
85SNR Estimation in dB is given by:
8686
87 SNR=10log(\frac{Rx}{Noise})
87SNR=10log(\frac{RxPower}{Noise})
8888
8989AWGN BER Estimation (QPSK)

9494Set the fading parameter to None''
9595\subsubsection{Very Low SNR}
96 Set the noise power to 98000000, which is equal to power of energy of the QPSK pulse generated by the TxDemo component. The resulting SNR=0 dB, and $E_b/N_0$=-3 dB.
96Set the noise power to 98000000, which is equal to power of energy of the QPSK pulse generated by the TxDemo component. The resulting SNR is 0 dB.
9797\osfig{IQ0dB}{I-Q Diagram, 0 dB SNR}
9898

108108...
109109\end{lstlisting}
110 Average bit error=0.16
111 Theorical bit error=0.1587
110The average bit error equals 0.16 which is very close the theoretical bit error of 0.1587.
112111\subsubsection{Low SNR}
113112Set noise power to 9800000

124123...
125124\end{lstlisting}
126
127 Average bit error=7.5e-4
128 Theoretical bit error=7.83e-4
125The Average bit error equals $7.5\times 10^{-4}$ which is also close to the theoretical bit error of $7.83\times 10^{-4}$
126
129127
130128\subsubsection{Medium SNR}

141139\end{lstlisting}
142140
143 Average bit error, to low to be estimated
144 Theoretical bit error=7.67e-24
141The average bit error is to low to be estimated, the theoretical bit error is $7.67\times 10^{-24}$.
145142
147 Set the fading parameter to Ricean''
148 Max. Doppler rate=0.001
144Set the fading parameter to Ricean'' and the Max. Doppler rate'' to 0.001. The theoretical bit error rate is not provided because is not as straightforward to estimate for the the conditions tested as the AWGN case.
150146Set the K fading factor'' to 0 (Rayleigh fading)
147It may be observed it the \osref{IQK0EnvelopeFalse} that both the amplitude and the phase of the received signal fluctuates.
151148\osfig{IQK0EnvelopeFalse}{I-Q Diagram, SNR=20 dB, K=0}
152149\begin{lstlisting}[]

164161...
165162\end{lstlisting}
166 Average bit error=0.353
163The average bit error equals to 0.353.
168165Set the K fading factor'' to 0 (Rayleigh fading)
169166Set the Envelope Fading Only'' to True
167
168It may be observed it the \osref{IQK0EnvelopeTrue} that only the amplitude of received signal fluctuates, there is not phase fluctuation.
170169\osfig{IQK0EnvelopeTrue}{I-Q Diagram, SNR=20 dB, K=0, Envelope Fading Only}
171170\begin{lstlisting}[]

183182...
184183\end{lstlisting}
185 Average bit error=6.84e-3
184Average bit error=$6.84\times 10^{-3}$
187186Set the K fading factor'' to 10
188187Set the Envelope Fading Only'' to False