Add example

This commit is contained in:
Ksyer
2024-05-09 16:54:58 +08:00
parent b91a609ca5
commit 17386d80c1
24 changed files with 3344 additions and 1 deletions
@@ -0,0 +1,276 @@
clc
clear
close all;
%% 参数设置
B = 5e6; % 信号带宽5MHz
Tp = 20e-6; % 脉宽100us
fs = 2 * B; % 采样频率
Ts = 1 / fs; % 采样周期
K = B / Tp; % 线性调频率
fc = 1.25e9; % 载波频率1.25GHz
PRF = 5000; % 脉冲重复频率
Tr = 1 / PRF; % 脉冲重复间隔
numP = 64; % 脉冲数量
t = 0: 1 / fs: Tr - 1 / fs;
tP = 0: 1 / fs: Tr * numP - 1 / fs;
c = 3e8; % 光速
slow_len = 128;
%%
sigma_n = 0.1;
alpha_prop = 0.8;
% SNR = -30;
SNR = [-5,0,5,8,10,12,15,20,25];
len_SNR = length(SNR);
P_fa = [1e-4, 5e-4, 1e-3, 5e-3, 1e-2, 5e-2, 1e-1, 5e-1, 1];
len_P_fa = length(P_fa);
rep_time = 500;
% rou >= c / 2B = 15(m)
%% 产生发射信号
N = Tr * fs;
N_high = Tp * fs;
signal_t = zeros(1, N * numP);
for j = 1: numP
for i = 1: N_high
tp = ((j - 1) * N + i) * (1 / fs);
signal_t(1, i + (j-1)*N) = exp(1j * 2 * pi * (fc * tp + 0.5 * K * tp .^ 2));
end
end
multiple_r = signal_t(1, 1: N) * signal_t(1, 1: N)';
% figure(1);
% subplot(311)
% plot(tP,real(signal_t));
% xlabel('时间/t');ylabel('幅度');
% title('发射信号');
%% 设置目标 1
distance1 = 18000;
v1 = 187.5;
tau1 = distance1 * 2 / c;
n_tau1 = round(tau1 * fs);
f_d1 = 2 * fc * v1 / c;
alpha1 = alpha_prop;
% alpha1 = 0;
signal_r1 = zeros(1, N * numP);
for j = 1: numP
for i = 1: N
temp = i - n_tau1;
if temp >= 1 && temp <= N_high
tp = ((j - 1) * N + i - n_tau1) * (1 / fs);
signal_r1(1, i + (j-1)*N) = alpha1 * exp(1j*2*pi*((fc - f_d1) * tp + 0.5 * K * tp .^ 2));
end
end
end
%% 生成回波
signal_r = signal_r1;
% figure(1);
% subplot(312)
% plot(tP, real(signal_r));
% xlabel('时间/t');
% ylabel('幅度');
% title('回波信号');
%%
P_fa_MF_cnt = zeros(len_SNR, len_P_fa, rep_time);
P_d_MF_cnt = zeros(len_SNR, len_P_fa, rep_time);
% 多普勒处理
F_ori = dftmtx(slow_len);
F = F_ori(1:numP,:);
multiple_d = F(:,1)' * F(:,1);
parfor rep = 1: rep_time
% for rep = 1: rep_time
for cnt_SNR = 1: len_SNR
%% 噪声处理
noise = random('Normal', 0, sigma_n/sqrt(2), 1, N * numP) + 1j * random('Normal', 0, sigma_n/sqrt(2), 1, N * numP);
alpha_SNR = sqrt(10^(SNR(cnt_SNR)/10) * sigma_n^2 / (multiple_r * multiple_d));
signal_r_n = signal_r * alpha_SNR + noise;
% figure(1);
% subplot(313)
% plot(tP, real(signal_r_n));
% xlabel('时间/t');
% ylabel('幅度');
% title('回波+噪声信号');
%% 匹配滤波——按Tr划分
Srange = zeros(N, numP);
% A = generate_matrix(transpose(signal_t(1, 1: N)), 1);
count_fa=0;
for i = 1: numP
sr = signal_r_n(1, 1 + (i - 1) * N: i * N);
st = signal_t(1, 1 + (i - 1) * N: i * N);
% A = generate_matrix(transpose(st), 1);
% mf = A' * transpose(sr);
% filterred_rf_r = mf ./ multiple_r;
% 匹配滤波
rf_r_fft_conj = conj(fft(st));
filterred_rf_r = ifft(fft(sr) .* rf_r_fft_conj);
filterred_rf_r = filterred_rf_r ./ multiple_r;
Srange(:,i) = filterred_rf_r';
end
% figure(101)
% mesh(abs(Srange))
% title('按Tr进行匹配滤波结果')
%% R匹配滤波——分布验证
% Before MF
% a+bi
% a~N(0,sigma_n^2 / 2)
% b~N(0,sigma_n^2 / 2)
% After MF
% a+bi
% a~N(0,sigma_n^2 / 2 / multiple_r)
% b~N(0,sigma_n^2 / 2 / multiple_r)
% a^2 + b^2 ~ chi^2(2) * sigma_n^2 / 2 / multiple_r
% stat_R = abs(Srange).^2;
% P_fa = 0.1;
% kd = sigma_n^2 * chi2inv(1 - P_fa, 2) / 2 / multiple;
% sum(sum(stat_R>kd))/numel(stat_R)
%% 多普勒滤波
Srd = zeros(N, slow_len);
for i = 1: N
% for i = 1201: 1201
% Srd(i, :) = fftshift(fft([Srange(i, :),zeros(1,slow_len-numP)]));
% x_slow = [Srange(i, :),zeros(1,slow_len-numP)];
% % y' = F * x'
% y_slow2 = F * transpose(x_slow);
y_slow2 = transpose(F) * transpose(Srange(i, :))./ multiple_d;
% figure(444)
% plot(abs(y_slow2))
Srd(i, :) = fftshift(transpose(y_slow2));
end
%% D匹配滤波——分布验证
% Before MF
% a+bi
% a~N(0,sigma_n^2 / 2 / multiple)
% b~N(0,sigma_n^2 / 2 / multiple)
% After MF
% a+bi
% a~N(0,sigma_n^2 / 2 / multiple_r / multiple_d)
% b~N(0,sigma_n^2 / 2 / multiple_r / multiple_d)
% a^2 + b^2 ~ chi^2(2) * sigma_n^2 / 2 / multiple_r / multiple_d
% 检测
target_node_d = round(v1 / (c / fc * PRF / 2 / slow_len)) + 1 + slow_len / 2;
target_node_r = n_tau1 + 1;
stat_D = abs(Srd).^2;
H0_index = zeros(size(Srd));
H0_index(target_node_r-N_high:target_node_r+N_high, :) = 1;
H0_index(target_node_r, target_node_d) = 0;
H1_index = zeros(size(Srd));
H1_index(target_node_r, target_node_d) = 1;
kd = sigma_n^2 * chi2inv(1 - P_fa, 2) / 2 / multiple_r / multiple_d;
for cnt_h_th = 1: len_P_fa
P_fa_MF_cnt(cnt_SNR, cnt_h_th, rep) = sum(sum(stat_D(H0_index > 0) > kd(cnt_h_th))) / sum(sum(H0_index));
P_d_MF_cnt(cnt_SNR, cnt_h_th, rep) = sum(sum(stat_D(H1_index > 0) > kd(cnt_h_th))) / sum(sum(H1_index));
end
end
fprintf('%d\n', rep);
end
P_fa_MF = mean(P_fa_MF_cnt, 3);
P_d_MF = mean(P_d_MF_cnt, 3);
%% plot
figure(1);
loglog(P_fa,P_fa_MF(1,:), 'linewidth', 2);
% hold on;
% grid on;
% loglog(P_fa,P_fa_MF(2,:), 'linewidth', 2);
% loglog(P_fa,P_fa_MF(3,:), 'linewidth', 2);
% loglog(P_fa,P_fa_MF(4,:), 'linewidth', 2);
% loglog(P_fa,P_fa_MF(5,:), 'linewidth', 2);
% loglog(P_fa,P_fa_MF(6,:), 'linewidth', 2);
% legend('SNR = 0','SNR = 2','SNR = 4','SNR = 6','SNR = 8','SNR = 10');
xlabel('P_fa');
ylabel('Actual P_fa');
figure(2);
semilogx(P_fa,P_d_MF(1,:), 'linewidth', 2);
% hold on;
% grid on;
% semilogx(P_fa,P_d_MF(2,:), 'linewidth', 2);
% semilogx(P_fa,P_d_MF(3,:), 'linewidth', 2);
% semilogx(P_fa,P_d_MF(4,:), 'linewidth', 2);
% semilogx(P_fa,P_d_MF(5,:), 'linewidth', 2);
% semilogx(P_fa,P_d_MF(6,:), 'linewidth', 2);
% legend('SNR = 0','SNR = 2','SNR = 4','SNR = 6','SNR = 8','SNR = 10');
xlabel('P_fa');
ylabel('P_d');
distance_temp = 0: (c / fs / 2) : (Tr * c / 2 - c / fs / 2);
speed_temp = (-PRF / 2: PRF / slow_len: PRF / 2 - PRF / slow_len) * (c / fc) / 2 ;
% save test_Rmf_Dmf.mat ...
% distance_temp...
% speed_temp...
% Srd...
% Srange...
% tP...
% signal_t...
% signal_r...
% signal_r_n...
% F...
% slow_len;
save test_MC_Pfa_Rmf_Dmf.mat ...
SNR...
P_fa...
P_fa_MF...
P_d_MF...
sigma_n...
B...
Tp...
fs...
Ts...
K...
fc...
PRF...
Tr...
numP...
t...
tP...
slow_len;