%CW%参考：声呐技术 P27，31clc;close all;clear all;%参数-------------------------f0=50;T=0.1;%时宽B=1/T;fs=1000;%采样频率Ts=1/fs;%采样时间N=T/Ts;%采样点个数t=linspace(0,T,N);y=exp(1i*2*pi*f0*t);%画图--------------------------------------------------------figure(1);subplot(2,1,1);plot(t,real(y));title('CW脉冲信号时域波形');xlabel('时间/s');ylabel('幅度');f=linspace(0,100,N);Y=T*(sin(pi*(f-f0)*T))./(pi*(f-f0)*T);subplot(2,1,2);plot(f,Y);title('CW脉冲信号频谱');xlabel('频率/Hz');ylabel('幅度');
%---------------------------------t=-T:0.01:T;v=-B:0.1:B;[t,v]=meshgrid(t,v);r=pi*v.*(T-abs(t));X=sin(r)./r.*(T-abs(t));%---------------------------------------figure(2);surf(t,v,abs(X));%模糊图t=linspace(0,T,N);
%---------------------------------------figure(3);v=15;c=1500;v0=f0*2*v/c;s=exp(1i*2*pi*f0*t).*exp(1i*2*pi*v0*t);subplot(2,1,1);plot(t,real(s));title('频移的CW脉冲信号时域波形');xlabel('时间/s');ylabel('幅度');Y=T*(sin(pi*(f-f0-v0)*T))./(pi*(f-f0-v0)*T);f=linspace(0,100,N);subplot(2,1,2);plot(Y);title('频移的CW脉冲信号频谱');xlabel('频率/Hz');ylabel('幅度');
%----------------------------------------------------------------------------------t=-T:0.01:T;v=5;v0=f0*2*v/c; %多普勒频移v0 %时延分辨力：rou=0.6T,频移分辨力rou：0.88/T；r=pi*v0.*(T-abs(t));X=sin(r)./r.*(T-abs(t)); %模糊函数figure(4);hold on;plot(t,abs(X),'red');t=-T:0.01:T;v=7;v0=f0*2*v/c;r=pi*v0.*(T-abs(t));X=sin(r)./r.*(T-abs(t));plot(t,abs(X));hold off;