pulse.m

对ASK调制解调进行了仿真,包括程序仿真和模型仿真

function [y,m]=pulse(x,m,Kmod);

if nargin<3; Komd=1;  end ;
if nargin<2; m=16;  end;
if nargin<1;  x=randint (1,32); end;
di=.5; Kmod=rem(Kmod,5); Kmod=(Kmod==0)*5+Kmod;
if Kmod ==1;
    xx= [x;x]; xx=xx(:)'; tstr='Unipolor NRZ';
elseif Kmod ==2;
    xx=[x;x];  xx=2*xx(:)' -1; tstr='Polor NRZ'
 elseif Kmod ==3;
    xx=[x; zeros(size(x))]; xx=xx(:)'; di=.2; tstr='Unipolor RZ';
  elseif Kmod==4;
      I=find(x ==1); x1=x(I); x1=rem(cumsum(x1),2) *2-1; xx=x;
      xx(I)=x1;
      xx= [xx;zeros(size(x))]; xx=xx(:)';di=.2; tstr='Bipolor RZ';
  elseif Kmod ==5;
      xx= [x;rem(x+1,2)]; xx=2*xx(:)' -1; tstr=' Manchester NRZ';
end;

y=xx;
for i=1: fix(m/2) -1; y= [y;xx]; end ;  y=y (:)';
if nargout<1; 
    subplot (211); plot(1+ (1: length(y))/m,y); hold on ;
    v=axis; axis( [v(1:2) -1.2 1.5]); zoom xon;
    if Kmod ==2 | Kmod ==0;
        plot([0 v(2)],[0 0],':');
    end; hold off ;
    set ( gcf, 'num','off','name', ...
        ['Binary Pulse Generator,''tstr','blanks (10)' ...
        'BBI 2000']);
    for i=1: length(x);
        text(i+di, 1.3,int2str(x(i)), 'color', 'b');
    end;
    title ('Pluse Signal');
    n=length (y); y=fft(y)/n; y=abs(y(1:fix(n/2))) *2;
    I=find (y<1e-04); y(I) =1e-04; y=20*log10(y);
    f1=m/n; f=0:f1:(length(y)-1)*f1;
    subplot(212); plot(f,y, 'r');
    title ('Power Spectrum'); xlabel('f/fb');
end;