雷達(dá)系統(tǒng)仿真matlab代碼(共5頁)

1、精選優(yōu)質(zhì)文檔-傾情為你奉上% =% 該程序完成16個(gè)脈沖信號(hào)的【脈壓、動(dòng)目標(biāo)顯示/動(dòng)目標(biāo)檢測（MTI/MTD）】 % =% 程序中根據(jù)每個(gè)學(xué)生學(xué)號(hào)的末尾三位（依次為XYZ）來決定仿真參數(shù)，034% 目標(biāo)距離為3000 8025 9000+(Y*10+Z)*200 8025，4個(gè)目標(biāo)% 目標(biāo)速度為50 0 (Y*10+X+Z)*6 100% =%close all; %關(guān)閉所有圖形clear all; %清除所有變量clc;% =% 雷達(dá)參數(shù) % =%C=3.0e8; %光速(m/s)RF=3.140e9/2; %雷達(dá)射頻 1.57GHzLambda=C/RF;%雷達(dá)工作波長PulseNumbe

2、r=16; %回波脈沖數(shù)BandWidth=2.0e6; %發(fā)射信號(hào)帶寬 帶寬B=1/，是脈沖寬度 TimeWidth=42.0e-6; %發(fā)射信號(hào)時(shí)寬PRT=240e-6; % 雷達(dá)發(fā)射脈沖重復(fù)周期(s),240us對(duì)應(yīng)1/2*240*300=36000米最大無模糊距離PRF=1/PRT;Fs=2.0e6; %采樣頻率NoisePower=-12;%(dB);%噪聲功率（目標(biāo)為0dB）% -%SampleNumber=fix(Fs*PRT);%計(jì)算一個(gè)脈沖周期的采樣點(diǎn)數(shù)480；TotalNumber=SampleNumber*PulseNumber;%總的采樣點(diǎn)數(shù)480*16=；BlindN

3、umber=fix(Fs*TimeWidth);%計(jì)算一個(gè)脈沖周期的盲區(qū)-遮擋樣點(diǎn)數(shù)；%=% 目標(biāo)參數(shù) %=% TargetNumber=4;%目標(biāo)個(gè)數(shù)SigPower(1:TargetNumber)=1 1 1 0.25;%目標(biāo)功率,無量綱TargetDistance(1:TargetNumber)=3000 8025 15800 8025;%目標(biāo)距離,單位m 距離參數(shù)為3000 8025 9000+(Y*10+Z)*200 8025 DelayNumber(1:TargetNumber)=fix(Fs*2*TargetDistance(1:TargetNumber)/C);% 把目標(biāo)距離換

4、算成采樣點(diǎn)（距離門） fix函數(shù)向0靠攏取整TargetVelocity(1:TargetNumber)=50 0 204 100;%目標(biāo)徑向速度 單位m/s 速度參數(shù)為50 0 (Y*10+X+Z)*6 100TargetFd(1:TargetNumber)=2*TargetVelocity(1:TargetNumber)/Lambda; %計(jì)算目標(biāo)多卜勒頻移2v/ %=% 產(chǎn)生線性調(diào)頻信號(hào) %=% number=fix(Fs*TimeWidth);%回波的采樣點(diǎn)數(shù)=脈壓系數(shù)長度=暫態(tài)點(diǎn)數(shù)目+1if rem(number,2)=0 %rem求余 number=number+1;end %把n

5、umber變?yōu)榕紨?shù) for i=-fix(number/2):fix(number/2)-1 Chirp(i+fix(number/2)+1)=exp(j*(pi*(BandWidth/TimeWidth)*(i/Fs)2);%exp(j*fi)*，產(chǎn)生復(fù)數(shù)矩陣Chirpendcoeff=conj(fliplr(Chirp);%把Chirp矩陣翻轉(zhuǎn)并把復(fù)數(shù)共軛，產(chǎn)生脈壓系數(shù)figure(1);%脈壓系數(shù)的實(shí)部plot(real(Chirp);axis(0 90 -1.5 1.5);title('脈壓系數(shù)實(shí)部');%-產(chǎn)生目標(biāo)回波串-%-產(chǎn)生前3個(gè)目標(biāo)的回波串-%SignalAl

6、l=zeros(1,TotalNumber);%所有脈沖的信號(hào),先填0for k=1:TargetNumber-1 % 依次產(chǎn)生各個(gè)目標(biāo) SignalTemp=zeros(1,SampleNumber);% 一個(gè)PRT SignalTemp(DelayNumber(k)+1:DelayNumber(k)+number)=sqrt(SigPower(k)*Chirp;%一個(gè)脈沖的1個(gè)目標(biāo)（未加多普勒速度）(DelayNumber(k)+1):(DelayNumber(k)+number) Signal=zeros(1,TotalNumber); for i=1:PulseNumber % 16個(gè)

7、回波脈沖 Signal(i-1)*SampleNumber+1:i*SampleNumber)=SignalTemp; %每個(gè)目標(biāo)把16個(gè)SignalTemp排在一起 end FreqMove=exp(j*2*pi*TargetFd(k)*(0:TotalNumber-1)/Fs);%目標(biāo)的多普勒速度*時(shí)間=目標(biāo)的多普勒相移 Signal=Signal.*FreqMove;%加上多普勒速度后的16個(gè)脈沖1個(gè)目標(biāo) SignalAll=SignalAll+Signal;%加上多普勒速度后的16個(gè)脈沖4個(gè)目標(biāo)end% %-產(chǎn)生第4個(gè)目標(biāo)的回波串-% fi=pi/3; SignalTemp=zeros

8、(1,SampleNumber);% 一個(gè)脈沖 SignalTemp(DelayNumber(4)+1:DelayNumber(4)+number)=sqrt(SigPower(4)*exp(j*fi)*Chirp;%一個(gè)脈沖的1個(gè)目標(biāo)（未加多普勒速度） Signal=zeros(1,TotalNumber); for i=1:PulseNumber Signal(i-1)*SampleNumber+1:i*SampleNumber)=SignalTemp; end FreqMove=exp(j*2*pi*TargetFd(4)*(0:TotalNumber-1)/Fs);%目標(biāo)的多普勒速度*

9、時(shí)間=目標(biāo)的多普勒相移 Signal=Signal.*FreqMove; SignalAll=SignalAll+Signal; figure(2);subplot(2,1,1);plot(real(SignalAll),'r-');title('目標(biāo)信號(hào)的實(shí)部');grid on;zoom on;subplot(2,1,2);plot(imag(SignalAll);title('目標(biāo)信號(hào)的虛部');grid on;zoom on; %=% 產(chǎn)生系統(tǒng)噪聲信號(hào) %=%SystemNoise=normrnd(0,10(NoisePower/10),

10、1,TotalNumber)+j*normrnd(0,10(NoisePower/10),1,TotalNumber);%均值為0，標(biāo)準(zhǔn)差為10(NoisePower/10)的噪聲%=% 總的回波信號(hào) %=%Echo=SignalAll+SystemNoise;% +SeaClutter+TerraClutter，加噪聲之后的回波for i=1:PulseNumber %在接收機(jī)閉鎖期,接收的回波為0 Echo(i-1)*SampleNumber+1:(i-1)*SampleNumber+number)=0; %發(fā)射時(shí)接收為0endfigure(3);%加噪聲之后的總回波信號(hào)subplot(2

11、,1,1);plot(real(Echo),'r-');title('總回波信號(hào)的實(shí)部,閉鎖期為0');subplot(2,1,2);plot(imag(Echo);title('總回波信號(hào)的虛部,閉鎖期為0');%=時(shí)域脈壓=%pc_time0=conv(Echo,coeff);%pc_time0為Echo和coeff的卷積pc_time1=pc_time0(number:TotalNumber+number-1);%去掉暫態(tài)點(diǎn) number-1個(gè)figure(4);%時(shí)域脈壓結(jié)果的幅度subplot(2,1,1);plot(abs(pc_ti

12、me0),'r-');title('時(shí)域脈壓結(jié)果的幅度,有暫態(tài)點(diǎn)');%pc_time0的模的曲線subplot(2,1,2);plot(abs(pc_time1);title('時(shí)域脈壓結(jié)果的幅度,無暫態(tài)點(diǎn)');%pc_time1的模的曲線% =頻域脈壓=%Echo_fft=fft(Echo,8192);%理應(yīng)進(jìn)行TotalNumber+number-1點(diǎn)FFT,但為了提高運(yùn)算速度,進(jìn)行了8192點(diǎn)的FFTcoeff_fft=fft(coeff,8192);pc_fft=Echo_fft.*coeff_fft;pc_freq0=ifft(pc_

13、fft);figure(5);subplot(2,1,1);plot(abs(pc_freq0(1:TotalNumber+number-1);title('頻域脈壓結(jié)果的幅度,有前暫態(tài)點(diǎn)');subplot(2,1,2);plot(abs(pc_time0(1:TotalNumber+number-1)-pc_freq0(1:TotalNumber+number-1),'r');title('時(shí)域和頻域脈壓的差別');pc_freq1=pc_freq0(number:TotalNumber+number-1);%去掉暫態(tài)點(diǎn) number-1個(gè),

14、后填充點(diǎn)若干(8192-number+1-TotalNumber)% =按照脈沖號(hào)、距離門號(hào)重排數(shù)據(jù)=%for i=1:PulseNumber pc(i,1:SampleNumber)=pc_freq1(i-1)*SampleNumber+1:i*SampleNumber);%每個(gè)PRT為一行，每行480個(gè)采樣點(diǎn)的數(shù)據(jù)endfigure(6);plot(abs(pc(1,:);title('頻域脈壓結(jié)果的幅度,沒有暫態(tài)點(diǎn)'); % =MTI（動(dòng)目標(biāo)顯示）,對(duì)消靜止目標(biāo)和低速目標(biāo)-可抑制雜波=%for i=1:PulseNumber-1 %滑動(dòng)對(duì)消，少了一個(gè)脈沖 mti(i,:)

15、=pc(i+1,:)-pc(i,:);endfigure(7);mesh(abs(mti);title('MTI result'); % =MTD（動(dòng)目標(biāo)檢測）,區(qū)分不同速度的目標(biāo)，有測速作用=%mtd=zeros(PulseNumber,SampleNumber);for i=1:SampleNumber buff(1:PulseNumber)=pc(1:PulseNumber,i); buff_fft=fft(buff); mtd(1:PulseNumber,i)=buff_fft(1:PulseNumber);end figure(8);mesh(abs(mtd);tit

16、le('MTD result');%=虛實(shí)矩陣轉(zhuǎn)換=%coeff_fft_c=zeros(1,2*8192);for i=1:8192 coeff_fft_c(2*i-1)=real(coeff_fft(i); coeff_fft_c(2*i)=imag(coeff_fft(i);endecho_c=zeros(1,2*TotalNumber);for i=1:TotalNumber echo_c(2*i-1)=real(Echo(i); echo_c(2*i)=imag(Echo(i);end%=以下是為DSP程序提供回波數(shù)據(jù)、脈壓系數(shù)=% fo=fopen('F:my studyVisual_DSP_testtest_1coeff_fft_c.dat','wt');%頻域