Add Example

2024-11-11 16:32:53 +08:00
parent a2cb6d1825
commit 29ae9585f9
56 changed files with 4029 additions and 0 deletions
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+clc;
+clear;
+close all;
+
+%% 参数设置
+sigma_n = 0.1;
+gamma = 0.5;
+
+% 信号参数
+B = 5e5;        %信号带宽
+Tp = 100e-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 = 1e8;       %载波频率
+
+Tr = 1e-3;
+
+t = 0: 1/fs: Tr - 1/fs;
+t2 = 0: 1/fs/2: Tr - 1/fs/2;
+
+c = 3e8; % 光速
+
+distance_max = (Tr-Tp) * c / 2;
+
+target_scattering = [0.8, 1, 0.9]; %扩展目标各点散射强度
+
+
+%% 生成矩阵 A
+% 生成发射信号 signal_t 及 
+N = Tr * fs;
+N_high = Tp * fs;
+
+signal_t  = zeros(1, N);
+signal_td  = zeros(1, N);
+for i = 1:N_high
+    tp = (i - 1) * (1 / fs);
+    signal_t(1, i) = exp(1j*2*pi*(fc*tp+0.5*K*tp.^2));
+    tp2 = (i - 0.5) * (1 / fs);
+    signal_td(1, i + 1) = exp(1j*2*pi*(fc*tp2+0.5*K*tp2.^2));
+end
+
+A = generate_matrix_new(signal_t.', signal_td.');
+
+J = A'*A;
+lambda_J=eig(J);
+
+figure(1)
+spy(A)
+
+
+%% 生成回波 y
+% 设置目标 - 扩展目标，由三个点组成
+distance1 = 52000;
+tau1 = distance1 * 2 / c;
+n_tau1 = round(tau1 * fs);
+
+alpha1 = 0.6; % 扩展目标整体散射强度
+signal_r1_t1  = zeros(1, N);
+signal_r2_t1  = zeros(1, N);
+signal_r3_t1  = zeros(1, N);
+
+for i = 1:N
+    temp = i - n_tau1;
+    if temp >= 1 && temp <= N_high
+        signal_r1_t1(1, i) = alpha1 * target_scattering(1) * signal_t(1, temp);
+        if i + 1 <= N
+            signal_r2_t1(1, i + 1) = alpha1 * target_scattering(2) * signal_t(1, temp);
+        end
+        if i + 1 <= N
+            signal_r3_t1(1, i + 2) = alpha1 * target_scattering(3) * signal_t(1, temp);
+        end
+    end
+end
+signal_r1 = signal_r1_t1 + signal_r2_t1 + signal_r3_t1;
+
+% 回波
+signal_r = signal_r1;
+
+% 加入噪声
+noise = random('Normal', 0, sigma_n/sqrt(2), 1, length(signal_r)) + 1j * random('Normal', 0, sigma_n/sqrt(2), 1, length(signal_r));
+signal_r_n = signal_r + noise;
+
+y = signal_r_n.';
+figure(2)
+subplot(211);
+plot(t, real(signal_t));
+title('发射信号')
+xlabel('时间')
+ylabel('幅度')
+
+subplot(212);
+plot(t, real(y))
+title('接收信号(y)')
+xlabel('时间')
+ylabel('幅度')
+
+%% 理论 x
+distance_node = round((distance1 * 2 / c) * fs);
+x_t = zeros(1, 2 * N);
+for i = 1: length(target_scattering)
+    x_t((distance_node + i) * 2 - 1) = alpha1 * target_scattering(i);
+end
+x = x_t.';
+
+figure(3)
+plot(t2, x);
+title('目标散射点(x)')
+xlabel('时间')
+ylabel('幅度')
+
+
+
+%% 验证
+y_t = A * x;
+y_r = signal_r.';
+
+figure(4)
+subplot(311);
+plot(real(y_r))
+title('实际回波')
+
+subplot(312);
+plot(real(y_t));
+title('计算结果')
+
+subplot(313);
+plot(abs(y_r - y_t));
+title('差异')
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