chirp信号脉冲压缩，用于雷达信号处理，产生chirp信号后进行压缩，以实现高距离分辨力

Posted 2021-07-07 fpga&matlab

% Author: Tian Liyu, BIT
% Date: Nov 16, 2009
% Description: chirp pulse compression
%matlab ver: 7.0.4,   R14

function  chirp_pc_result = Chirp_Pulse_Comp(LFM_Fre_Width, LFM_T_Width, Window_Type, Fs)

T = [0: 1/Fs : LFM_T_Width];
F0 = -LFM_Fre_Width/2;
%F0 = 0;        %如果F0=0, 加窗后脉压的结果中的主瓣有分裂;  用复chirp信号仿真就不存在这个问题
T1 = LFM_T_Width;
F1 = F0 + LFM_Fre_Width;
chirp_echo = chirp(T,F0,T1,F1);
figure(1)
plot(chirp_echo);
title('chirp回波信号')

%chirp_MF:  chirp脉压的匹配滤波器, 信号的(共轭)反转
chirp_MF = chirp_echo(length(chirp_echo) : -1 : 1);

win_len = length(chirp_echo);
%加窗
windows_chirp = ones( win_len , 1).';
switch Window_Type
    case 0,
        windows_chirp = ones( win_len , 1).';   %矩形窗
    case 1,
        windows_chirp = hamming( win_len ).';
    case 2,
        windows_chirp = hanning( win_len ).';
    case 3,
        windows_chirp = blackman( win_len ).';
    otherwise,
end

chirp_MF = chirp_MF .* windows_chirp;

%chirp脉冲压缩
chirp_pc_result = abs(conv(chirp_echo, chirp_MF));
figure(2)
plot(chirp_pc_result);
title('chirp脉压的结果')

figure(3)
plot(20*log10(chirp_pc_result/max(chirp_pc_result)));
title('chirp脉压的结果(dB表示)')
ylabel('dB');
grid

 

D84