yantu.sci

基于scilab软件的gmsk信号的调制

function y=g(t);
//global a T B

T=1/270833;
B=0.3/T;
a=sqrt(log(2)/2)/B;
s1=4*T;
y=erfc(%pi*(t-T/2)/a)/s1-erfc(%pi*(t+T/2)/a)/s1;

endfunction;

f=270833;
dt=1/f;
times=100;
Na=10;
yang=8;
M=Na*times;
N=M*yang;
%f=270833;
T=1/f;
B=0.3/T;
Q=10;
jifen=zeros(1,5);
q=zeros(1,5);
c=zeros(1,5);
cossum=zeros(1,1024);
sinsun=zeros(1,1024);
xiangwei=zeros(1,1024);
 for n=0:31  
   for L=0:3
        
        m=n;                
            n1=fix(m/16);
            if n1,m=n-16;end;
            n2=fix(m/8);
            if n2,m=m-8;end;
            n3=fix(m/4);
            if n3,m=m-4;end;
            n4=fix(m/2);
            if n4,m=m-2;end;
            n5=m;
            
            b1=n1;              
            if b1==0,b1=-1;end;
            b2=n2;
            if b2==0,b2=-1;end;
            b3=n3;
            if b3==0,b3=-1;end;
            b4=n4;
            if b4==0,b4=-1;end;
            b5=n5;
            if b5==0,b5=-1;end;
         
           for ii=1:8
            jifen(1)=intg(-2.5*T,1.5*T+T*ii/8,g);
            jifen(2)=intg(-2.5*T,0.5*T+T*ii/8,g);
            jifen(3)=intg(-2.5*T,-0.5*T+T*ii/8,g);
            jifen(4)=intg(-2.5*T,-1.5*T+T*ii/8,g);
            jifen(5)=intg(-2.5*T,-2.5*T+T*ii/8,g);
            q=b1*jifen(1)+b2*jifen(2)+b3*jifen(3)+b4*jifen(4)+b5*jifen(5);
            x=n*32+L*8+ii;
           
            xiangwei(x)=%pi*q+L*%pi/2;
            cossum(n*32+L*8+ii)=cos(xiangwei(n*32+L*8+ii));
            sinsum(n*32+L*8+ii)=sin(xiangwei(n*32+L*8+ii));
            
        end;
    end;
end;
 xiangwei;
 
 
 
an=round(rand(1,M+1));
fai=0;
bn=zeros(1,M);
dn=zeros(1,M+5);
cn=zeros(1,M+5);
for nn=1:M
   // cn(nn)=xor(an(nn),an(nn+1));
  if an(nn)==an(nn+1),cn(nn)=0;
  else 
    cn(nn)=1;
 end;
 
   
   cn(nn+5)=cn(nn);
    dn(nn)=cn(nn);
    if cn(nn)==0, cn(nn)=-1;
    end;
    
end;

cosfai=zeros(1,M*yang);
sinfai=zeros(1,M*yang);

for mm=1:M
    fai=fai+cn(mm);
    xx=pmodulo(fai,4);
    xxaddress=xx*8+(dn(mm+1)*16+dn(mm+2)*8+dn(mm+3)*4+dn(mm+4)*2+dn(mm+5))*32;
    for kk=1:8
        xiang=xxaddress+kk;
        cosfai((mm-1)*8+kk)=cossum(xiang);
        sinfai((mm-1)*8+kk)=sinsum(xiang);
    end;
end;
ttt=0:Na*yang;

for jj=1:Na*yang:N-Na*yang                       //画cos的眼图
    plot(ttt,cosfai(jj:jj+Na*yang));         
end