线性调频信号干扰仿真

function

[y]=pc_matched_filiter_53(b,taup,Rmax,scat_range,RCS,val,f0,delay,val1,N_A,val2,val3,val4,val5,R1,R max2,val6,val7)

if nargin==0

Rmax=40;taup=10;b=30;scat_range=[15];RCS=[1];delay=300;f0=[0];val=0;val1=0;N_A=1;val2=1;val3= 0;val4=0;val5=0;R1=10;Rmax2=20;val6=0;val7=0;

end

unit=1e3;

unit2=1e6;

unit3=1e-6;

Rmax=Rmax*unit;

R1=R1*unit;

Rmax2=Rmax2*unit;

b=b*unit2;

taup=taup*unit3;

delay=delay*unit3;

scat_range=scat_range*unit;

f=1e6.*f0;

c = 3.e8;

Rwid=Rmax2-R1; %receive window in meter

Twid=2*Rwid/c; %receive window in second

Fs=5*b;Ts=1/Fs; %sampling frequency and sampling spacing Nwid=ceil(Twid/Ts); %receive window in number

% number of samples

n = fix(5 * taup * b);%n=2500

s = taup * c /2;%s=750.0000

Npoints = ceil(Rmax * n /s);%终端Npoints =1334

% calculate sampling interval

%线性调频信号：：：：：：：：：：：：：：：：：：

t0=linspace(-taup/2,taup/2,n);

replica = exp(j * pi * (b/taup) .* t0.^2);

%固定目标回波：：：：：：：：：：：：：：：：：：：：：：：：：：：：：：

t = linspace(0,2*Rmax/c,Npoints);

t2=linspace(2*R1/c,2*Rmax2/c,Nwid);

M=length(scat_range);

td=ones(M,1)*t-2*scat_range'/c*ones(1,Npoints);

td2=ones(M,1)*t2-2*scat_range'/c*ones(1,Nwid);

%能量衰减参数L：：：：：：：：：：：：：：：：：：：：：：：：：：：：：：

L1=scat_range*1e-6;

L=L1.^2.5;

y=RCS./L*(exp(j*pi*(b/taup)*(td).^2).*(abs(td)

y2=RCS./L*(exp(j*pi*(b/taup)*(td2).^2).*(abs(td2)

%移频干扰val7：：：：：：：：：：：：：：：：：：：：：：：：：：：：：：：：

if ~val7

%延时干扰val6：：：：：：：：：：：：：：：：：：：：：：：：：：：：：：：：：：

if~val6

replica11=y;

replica21=y2;

else

replica11=RCS./L*(exp(j*pi*(b/taup)*(td-delay).^2).*(abs(td)

replica21=RCS./L*(exp(j*pi*(b/taup)*(td2-delay).^2).*(abs(td2)

end

else

if~val6

replica11=y;

replica21=y2;

else

replica11=RCS./L*(exp(j*pi*(b/taup)*(td-delay).^2).*(abs(td)

replica21=RCS./L*(exp(j*pi*(b/taup)*(td2-delay).^2).*(abs(td2)

end

replica1=exp(-j*2*pi*f.*td);

replica11=replica11.*replica1;

replica2=exp(-j*2*pi*f.*td2);

replica21=replica21.*replica2;

end

if val4

noise=sqrt(N_A)*randn(size(replica));

plot(t,noise);ylabel(' noise');xlabel('time in seconds');grid;

else

if val3

if val2

plot(t0,real(replica));ylabel('Real (part) of replica');xlabel('time in seconds');grid;

else

sampling_interval = taup / n;

freqlimit = 0.5/ sampling_interval;

freq = linspace(-freqlimit,freqlimit,n);

plot(freq,fftshift(abs(fft(replica))));ylabel('Spectrum of replica');xlabel('Frequency in Hz');grid;

end

else

if val

if val1

noise=sqrt(N_A)*randn(1,length(y));

y=y+noise;

end

%A型和A/R型显示器选择val5：：：：：：：：：：：：：：：：：：

if ~val5

subplot(20,20,[1 10 21 30 61 70 81 90 121 130 161 170 221 230 261 270 321 330 361 370]);

plot(t*1e6,real(y),'B');xlabel('Time in u sec');ylabel('Amplitude');ylabel ('Uncompressed echo');grid;

else

subplot(20,20,[1 10 21 30 61 70 81 90 121 130 141 150 161 170]);