Matlab实现FMCW雷达仿真

clc,close all,clear; %% parameters f0 = 24.125e9; %% center freq, unit: Hz fm = 100; %% unit: Hz tm = 1/fm; %% unit: s N = 1024; %% points of FFT trans B = 100e6; %% mod bandwidth, unit: Hz C = 3e8; %% speed of light, unit: m/s d_2p = 0.014; %% distance between two echo antennas, unit: m fs = 256e3; %% AD sample rate, unit: Hz t = 0:1/fs:1; %% range of time domin( 1 second ) %% window function type, length of window is the same as FFT win = chebwin(N); %% user define ang_simu = 2; %% angle base on normal line, unit: ?? ang_hd = ang_simu/360*2*pi; %% angle base on normal line, unit: rad diff_refr = sin(ang_hd)*d_2p; %% distance_diff of two echos, unit: m ang_hd_lamda = diff_refr*f0/C*2*pi; %% phase_diff of two echos, unit; rad r = 90; %% distance base on normal point, unit: m tao1 = 2*r/C + diff_refr/C; %% delay of echo1, unit: s tao2 = 2*r/C; %% delay of echo2, unit: s %% signals, after mix s1_mix_i = cos(2*pi*(f0 - B*0.5)*tao1 + 2*pi*B*tao1.*t/tm); s1_mix_q = sin(2*pi*(f0 - B*0.5)*tao1 + 2*pi*B*tao1.*t/tm); s2_mix_i = cos(2*pi*(f0 - B*0.5)*tao2 + 2*pi*B*tao2.*t/tm); s2_mix_q = sin(2*pi*(f0 - B*0.5)*tao2 + 2*pi*B*tao2.*t/tm); %% DSP for i = 1:250 %% in 1s, if points of FFT are 1024, fs = 256e3, i_max = fs/N = 250 %%%% each fft needs 1024 points of digital signal xout_1i = s1_mix_i((i-1)*N+1:N*i); xout_1q = s1_mix_q((i-1)*N+1:N*i); xout_2i = s2_mix_i((i-1)*N+1:N*i); xout_2q = s2_mix_q((i-1)*N+1:N*i); %%%% I channel & Q channel combine to complex cout_1 = complex(xout_1i,xout_1q); cout_2 = complex(xout_2i,xout_2q); %%%% add win %%%% wout_1 = cout_1.*win'; wout_2 = cout_2.*win'; %%%% two diff_signal fft trans %%%% fout_1 = fft(wout_1); fout_2 = fft(wout_2); %%%% distance (choose channel no.1)%%%% position = find(abs(fout_1) == max(abs(fout_1))); freq = position/N*fs; L_target(i) = C*tm*freq/(2*B); %%%% phase (need 2 channels) %%%% diff_ang = angle(wout_1(1)) - angle(wout_2(1)); diff = diff_ang/(2*pi)*(C/f0); sin_sita = diff/d_2p; angle_result(i) = asin(sin_sita); A_target(i) = angle_result(i)*360/(2*pi); %%%%%%% counter %%%%%%%% if(mod(i,10) == 0) i end end %% polar can give the relationship between angle and distance figure;polar(angle_result,L_target,'*r');