pathloss.m

Electronic Communication Systems的Matlab源码

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% Received power as a percentage of the transmitted power, taking into acount
% free-space loss, receiver input impedance mismatch and a
% transmitter receiver spacing of 20km to 100km
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tx_freq=input('Enter the Transmitter carrier frequency in Megahertz  ');
tx_len=input('Enter the transmission line length in metres  ');
tx_loss=input('Enter the transmission line loss in dB per metre  ');
tx_gain=input('Enter the transmitter antenna gain in dB  ');
rx_gain=input('Enter the receiver antenna gain in dB  ');
rx_char_imp=input('Enter the receiver input line characteristic impedance in ohms  ');
rx_input_imp=input('Enter the receiver input impedance in ohms  ');


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% vector of distances from 20km to 100km
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d=20:0.1:100;
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% Free-space loss computation
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Lfs=32.44+20*log10(d)+20*log10(f)-tx_gain-rx_gain;
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% Transmitter line loss
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Ltx=tx_len*tx_loss;

tau = (rx_input_imp-rx_char_imp)/(rx_input_imp+rx_char_imp);

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% Loss at receiver
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Lrx = -10*log10(1-tau.^2);

% Overall loss
Lt= Lfs + Ltx + Lrx;

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% received power as a percentage of transmitted power
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efficiency=100*10.^(-1*Lt/10);

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% Plot efficiency versus distance
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clf
figure(1)

plot(d,efficiency);
title('Percentage Efficiency for various transmitter receiver spacing')
ylabel('Percentage')
xlabel('transmitter receiver spacing in km')
grid
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