Matlab Code for Satellite Link Budget

clear all;

clc;

disp('ENTER UPLINK PARAMETERS')

disp('---------------------------------------')

pt=input('Earth station Transmitter output power :');

lbo=input('Earth Station back-off loss : ');

lbf=input('Earth station branching and feeder losses :');

at=input('Earth station Transmit antenna gain : ');

lu=input('Additional uplink atmospheric losses : ');

lp=input('Free-space path loss : ');

gte=input('Satellite receiver G/Te ratio : ');

bfb=input('Satellite branching and feeder losses : ');

br=input('Bit rate : ');

disp('---------------------------------------')

disp('ENTER DOWNLINK PARAMETERS')

disp('---------------------------------------')

disp('')

pt2=input('Satellite transmitter output power :');

lbo2=input('Satellite back-off loss : ');

lbf2=input('Satellite branching and feeder losses :');

at2=input('Satellite Transmit antenna gain : ');

ld=input('Additional downlink atmospheric losses : ');

lp2=input('Free-space path loss : ');

gte2=input('Earth station receiver G/Te ratio : ');

bfb2=input('Earth station branching and feeder losses : ');

br2=input('Bit rate : ');

disp('---------------------------------------')

EIRP=pt+at-lbo-lbf;

disp('UPLINK BUDGET')

disp('---------------------------------------')

%EIRP (Earth Station)

fprintf('EIRP (Earth Station) = %f dBW \n',EIRP);

c1=EIRP-lp-lu;

%Carrier power density at the satellite antenna :

fprintf('Carrier power density at the satellite antenna = %f dBW\n',c1);

cn0=c1+gte-(10*log10(1.38*(10^(-23))));

fprintf('C/No at the satellite = %f dB\n',cn0);

ebn0=cn0-(10*log10(br));

fprintf('Eb/No : = %f dB\n',ebn0);

cn=ebn0-10*(log10((40*(10^6))/(br)));

fprintf('for a minimum bandwidth system, C/N = %f dB\n',cn);

disp('---------------------------------------')

disp('DOWNLINK BUDGET')

disp('---------------------------------------')

%EIRP (satellite transponder)

EIRP2=pt2+at2-lbo2-lbf2;

fprintf('EIRP (satellite transponder) = %f dBW \n',EIRP2);

c12=EIRP2-lp2-ld;

%Carrier power density at the earth station antenna :

fprintf('Carrier power density at earth station antenna = %f dBW\n',c12);

cn02=c12+gte2-(10*log10(1.38*(10^(-23))));

fprintf('C/No at the earth station receiver = %f dB\n',cn02);

ebn02=cn02-(10*log10(br2));

fprintf('Eb/No : = %f dB\n',ebn02);

cn2=ebn02-10*(log10((40*(10^6))/(br2)));

fprintf('for a minimum bandwidth system, C/N = %f dB\n',cn2);

a=10^(ebn0/10);

b=10^(ebn02/10);

ebn0all=(a*b)/(a+b);

ebn02db=10*log10(ebn0all);

fprintf('Eb/No(overall) : = %f dB\n',ebn02db);

SAMPLE INPUT 

ENTER UPLINK PARAMETERS

---------------------------------------

Earth station Transmitter output power :33

Earth Station back-off loss : 3

Earth station branching and feeder losses :4

Earth station Transmit antenna gain : 64

Additional uplink atmospheric losses : .6

Free-space path loss : 206.5

Satellite receiver G/Te ratio : -5.3

Satellite branching and feeder losses : 0

Bit rate : 120*(10^6)

---------------------------------------

ENTER DOWNLINK PARAMETERS

---------------------------------------

Satellite transmitter output power :10

Satellite back-off loss : .1

Satellite branching and feeder losses :.5

Satellite Transmit antenna gain : 30.8

Additional downlink atmospheric losses : .4

Free-space path loss : 205.6

Earth station receiver G/Te ratio : 37.7

Earth station branching and feeder losses : 0

Bit rate : 120*(10^6)