mKuBand_Question4.m

% 1.	Design a transmitting earth station (using Matlab) to provide a clear 
% air C/N of 30 dB in a Ku-Band transponder at a frequency of 14.15 GHz. 
% Use an uplink antenna with a diameter of 5 meters and an aperture 
% efficiency of 68 %, and find the uplink transmitter power required 
% to achieve the required C/N of 26 dB. 
% The uplink station is located on the 2-dB contour of the satellite footprint. 
% Allow 1 dB for clear air atmospheric attenuation and other losses. 


% Constants
c = 3e8; % Speed of light (m/s)
f_UL = 14.15e9; % Frequency (Hz)
BW_tr_Hz = 36e6; % Transponder Bandwidth (Hz)
BW_tr_dB = 10*log10(BW_tr_Hz);
R = 38500e3; % Distance (m)
D = 5; % Antenna diameter (m)

K = -228.6; % Boltzmann constant (dBW/K/Hz)
T_sys = 500; % Noise temperature (K)
T_sys_dB = 10*log10(T_sys); 

Pt_sat_W = 40; % Saturated output power of the satellite
Pt_sat_db = 10*log10(Pt_sat_W);
G_sat_dB = 31; % Antenna gain
G_sat_lin = 10^(G_sat_dB / 10); 
FEC_dB = 5.5;

Aeff_ES = 0.68; % Antenna aperture efficiency
reqCN_up_dB = 30; % Required carrier-to-noise ratio (dB)
L_ptr = 2; % Edge of contour Loss in dB
L_misc = 1; % Clear air atmospheric attenuation and other losses in dB
Gr_sat_dB = G_sat_dB - L_ptr;

% Calculate wavelength
lambda = c / f_UL;

%% 1. Noise Power Budget (C/N)up = 26 dB
N_dB = K + T_sys_dB + BW_tr_dB; % Power of the Noise in dB
fprintf('The noise power is: %.2f dBW\n', N_dB);
Pr_sat_dB = N_dB + reqCN_up_dB; % The received power level must be 
% 26 dB greater than the noise power
fprintf('The required satellite received power is: %.2f dBW\n', Pr_sat_dB);

%% 1. Calculate losses
Lp = 20 * log10(R) + 20 * log10(f_UL) + 20 * log10(4 * pi / c);
fprintf('The free-space path loss is: %.2f dB\n', Lp);
L_tot_dB = Lp + L_misc;
fprintf('The total loss is: %.2f dB\n', L_tot_dB);

%% 2. Calculate antenna gain
Gt_lin = Aeff_ES * (pi * D / lambda)^2;
fprintf('The linear antenna gain is: %.2f\n', Gt_lin);

%% 3. Convert antenna gain to dB
Gt_db = 10 * log10(Gt_lin);
fprintf('The antenna gain in dB is: %.2f dB\n', Gt_db);

%% 4. Calculate required transmitter power
Pt_dB = reqCN_up_dB - (Gt_db + Gr_sat_dB - Lp - N_dB);
fprintf('The required transmitter power is: %.2f dBW\n', Pt_dB);

%% 5. Convert power to W
Pt_W = 10^(Pt_dB/10);
fprintf('The required transmitter power is: %.2f W\n', Pt_W);

%% 6. Get (C/N)up
CN_up = Pt_dB - N_dB;
fprintf('The carrier-to-noise ratio (C/N) uplink is: %.2f dB\n', CN_up);

%% 7. Show Results
fprintf('The required transmitter output power during clear sky conditions is: %.2f Watts (%.2f dBW)\n', Pt_W, Pt_dB);