gailv1.m

多模光纤的信道特性研究

x=0.1;N=20;
a=ones(1,N);
y=exp(-pi*x^2/4);
for i=2:N
    a(i)=i*a(i-1);
end
for k=1:10
    j=k;z=N-j;
    x(j)=a(j)*a(N-j);
    A(j)=a(N)/x(j);
    B(j)=(1-y)^j;
    C(j)=y^z;
    P1(j)=A(j)*B(j)*C(j); 
end

x=0.1;N=30;
a=ones(1,N);
y=exp(-pi*x^2/4);
for i=2:N
    a(i)=i*a(i-1);
end
for k=1:10
    j=k;z=N-j;
    x(j)=a(j)*a(N-j);
    A(j)=a(N)/x(j);
    B(j)=(1-y)^j;
    C(j)=y^z;
    P2(j)=A(j)*B(j)*C(j); 
end

x=0.1;N=40;
a=ones(1,N);
y=exp(-pi*x^2/4);
for i=2:N
    a(i)=i*a(i-1);
end
for k=1:10
    j=k;z=N-j;
    x(j)=a(j)*a(N-j);
    A(j)=a(N)/x(j);
    B(j)=(1-y)^j;
    C(j)=y^z;
    P3(j)=A(j)*B(j)*C(j); 
end

x=0.1;N=50;
a=ones(1,N);
y=exp(-pi*x^2/4);
for i=2:N
    a(i)=i*a(i-1);
end
for k=1:10
    j=k;z=N-j;
    x(j)=a(j)*a(N-j);
    A(j)=a(N)/x(j);
    B(j)=(1-y)^j;
    C(j)=y^z;
    P4(j)=A(j)*B(j)*C(j); 
end
k=1:10;
figure,plot(k,P1,'-+',k,P2,':d',k,P3,'-.h',k,P4,'--x') 
legend('N=20','N=30','N=40','N=50')
grid on
xlabel('落在衰落点上的载波数k'),ylabel('概率 P');