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 65 65 66 66 \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. 67 This 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. 70 68 71 69 \section{Procedure} … … 79 77 \subsection{Getting Started} 80 78 \subsection{Building the waveform} 79 Using 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} 81 80 \osfig{waveformOEF}{OEF Waveform Structure} 82 81 \osfig{blockdiagram}{Block Diagram} 83 82 \osfig{wfmproperties}{Initial Channel Component Properties} 84 83 \subsection{Theory} 85 SNR Estimation 84 The TxDemo transmits QPSK symbols with energy $7000^2+7000^2=98000000$ (both I and Q components have an amplitude of 7000). 85 SNR Estimation in dB is given by: 86 86 \begin{equation} 87 SNR=10log(\frac{Rx }{Noise})87 SNR=10log(\frac{RxPower}{Noise}) 88 88 \end{equation} 89 89 AWGN BER Estimation (QPSK) … … 94 94 Set the fading parameter to ``None'' 95 95 \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 $E_b/N_0$=3dB.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 is 0 dB. 97 97 \osfig{IQ0dB}{IQ Diagram, 0 dB SNR} 98 98 … … 108 108 ... 109 109 \end{lstlisting} 110 Average bit error=0.16 111 Theorical bit error=0.1587 110 The average bit error equals 0.16 which is very close the theoretical bit error of 0.1587. 112 111 \subsubsection{Low SNR} 113 112 Set noise power to 9800000 … … 124 123 ... 125 124 \end{lstlisting} 126 127 Average bit error=7.5e4 128 Theoretical bit error=7.83e4 125 The Average bit error equals $7.5\times 10^{4}$ which is also close to the theoretical bit error of $7.83\times 10^{4}$ 126 129 127 130 128 \subsubsection{Medium SNR} … … 141 139 \end{lstlisting} 142 140 143 Average bit error, to low to be estimated 144 Theoretical bit error=7.67e24 141 The average bit error is to low to be estimated, the theoretical bit error is $7.67\times 10^{24}$. 145 142 146 143 \subsection{Fading} 147 Set the fading parameter to ``Ricean'' 148 Max. Doppler rate=0.001 144 Set 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. 149 145 \subsubsection{Rayleigh Fading} 150 146 Set the ``K fading factor'' to 0 (Rayleigh fading) 147 It may be observed it the \osref{IQK0EnvelopeFalse} that both the amplitude and the phase of the received signal fluctuates. 151 148 \osfig{IQK0EnvelopeFalse}{IQ Diagram, SNR=20 dB, K=0} 152 149 \begin{lstlisting}[] … … 164 161 ... 165 162 \end{lstlisting} 166 Average bit error=0.353 163 The average bit error equals to 0.353. 167 164 \subsubsection{Rayleigh Fading  Envelope Fading Only} 168 165 Set the ``K fading factor'' to 0 (Rayleigh fading) 169 166 Set the ``Envelope Fading Only'' to True 167 168 It may be observed it the \osref{IQK0EnvelopeTrue} that only the amplitude of received signal fluctuates, there is not phase fluctuation. 170 169 \osfig{IQK0EnvelopeTrue}{IQ Diagram, SNR=20 dB, K=0, Envelope Fading Only} 171 170 \begin{lstlisting}[] … … 183 182 ... 184 183 \end{lstlisting} 185 Average bit error= 6.84e3184 Average bit error=$6.84\times 10^{3}$ 186 185 \subsubsection{Ricean Fading} 187 186 Set the ``K fading factor'' to 10 188 187 Set the ``Envelope Fading Only'' to False 188 It 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. 189 189 \osfig{IQK10EnvelopeFalse}{IQ Diagram, SNR=20 dB, K=10} 190 Notice that there is a much less severe phase and amplitude shift 190 191 191 \begin{lstlisting}[] 192 192 ...