Changeset 9406

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06/10/09 17:13:12 (6 years ago)
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hvolos
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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\begin{equation} 
    87 SNR=10log(\frac{Rx}{Noise}) 
     87SNR=10log(\frac{RxPower}{Noise}) 
    8888\end{equation} 
    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 
    146143\subsection{Fading} 
    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. 
    149145\subsubsection{Rayleigh Fading} 
    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.  
    167164\subsubsection{Rayleigh Fading - Envelope Fading Only} 
    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=$6.84\times 10^{-3}$ 
    186185\subsubsection{Ricean Fading} 
    187186Set the ``K fading factor'' to 10 
    188187Set the ``Envelope Fading Only'' to False 
     188It may be observed it the \osref{IQK10EnvelopeFalse} that both the amplitude and the phase of the received signal fluctuates less severely compared to the K=0 case. 
    189189\osfig{IQK10EnvelopeFalse}{I-Q Diagram, SNR=20 dB, K=10} 
    190 Notice that there is a much less severe phase and amplitude shift 
     190 
    191191\begin{lstlisting}[] 
    192192...