69 lines
2.2 KiB
Matlab
69 lines
2.2 KiB
Matlab
clear all
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close all
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clc
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c0 = physconst('LightSpeed');
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fc = 76.5e9;
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lambda_c = c0 / fc;
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k_c = 2 * pi / lambda_c;
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num_tgt = 2;
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Ntar_sample = 300;
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tar_loc_x = linspace(-2.5, 2.5, num_tgt);
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tar_loc_y = linspace(18, 350, Ntar_sample);
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tar_loc_z = zeros(1, num_tgt);
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for tidx = 1 : num_tgt
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tar_xyz(:,:,tidx) = [tar_loc_x(tidx)*ones(Ntar_sample,1) tar_loc_y' tar_loc_z(tidx)*ones(Ntar_sample,1)];
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[azimuth, elevation, r] = cart2sph(tar_xyz(:,1,tidx), tar_xyz(:,2,tidx), tar_xyz(:,3,tidx));
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tar_scs(:,:,tidx) = [rad2deg(pi/2 - azimuth) rad2deg(elevation) r];
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end
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Pt = 13; % [dBm]
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Pt = Pt - 30; % [dBW]
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NF = 12; % [dB]
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T0 = 300; % [K]
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kb = physconst('Boltzmann');
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BW_int = 40e6; % [Hz] instantaneous Bandwidth
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% Target RCS
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rcs = 10; % [dBsm]
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% Noise & Quantization error power
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%[~, Qnf] = quanttemp(T0, 12, 'DynamicRange', 52); % ADC bit : 12 [bits], Dynamic Range : 52 [dB] (NXP chip)
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%Qnf = 0;
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N_bits = 12;
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Qnf = -1 * (6.02*N_bits + 10*log10(BW_int) + 1.76) - 30;
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Pnq = pow2db(kb * T0) + NF + Qnf + pow2db(BW_int); % [dBW]
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% Antenna patter loading
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load('azi_ant_pat.mat');
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% azi_ant_pat(:,2) = azi_ant_pat(:,2) -16.3 + 15;
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load('elev_ant_pat.mat');
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% elev_ant_pat(:,2) = elev_ant_pat(:,2) -16.3 + 15;
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for tidx = 1 : num_tgt
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tar_ant_gain(:, tidx) = interp1(azi_ant_pat(:,1), azi_ant_pat(:,2), tar_scs(:,1,tidx));
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tar_elev_ant_gain_reduction = interp1(elev_ant_pat(:,1), elev_ant_pat(:,2), 0) - interp1(elev_ant_pat(:,1), elev_ant_pat(:,2), tar_scs(:,2,tidx));
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tar_ant_gain(:, tidx) = tar_ant_gain(:,tidx) - tar_elev_ant_gain_reduction;
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end
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% Losses & SP gains
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L_sf = 3; % [dB] secondary surface loss
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L_ant = 2.5; % [dB] Feeder and Radome loss
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L_win = 2.38 + 1.36; % [dB] loss by windowing in 2D
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L_straddle = 2.88; % [dB] straddle loss(worst)
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L_q = 1; % [dB] Quantization loss
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L_sp = 1; % [dB] Other signal processing losses
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L_total = L_sf + L_ant + L_win + L_straddle + L_q + L_sp;
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NFFT_R = 512;
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NFFT_D = 256;
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G_sp = pow2db(NFFT_R * NFFT_D); % [dB] Signal processing gain by 2D-FFT
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% SNR calculation
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for tidx = 1 : num_tgt
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SNR_set(:,tidx) = Pt + pow2db((lambda_c^2) / (4*pi)^3) + pow2db(1./tar_scs(:,3,tidx).^4) + tar_ant_gain(:,tidx) + tar_ant_gain(:,tidx) + rcs - L_total + G_sp - Pnq;
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end
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