uwbmod.m

该程序仿真超宽带的脉冲位置调制。是在MATLAB下实现的。

function [sys,x0,str,ts] = UWBmod(t,x,u,flag,modType,pulseType,sigPower,tau,Tf,Tc,delta,M,link,xini,bitsPerHop,Ts)

switch flag,

  %%%%%%%%%%%%%%%%%%
  % Initialization %
  %%%%%%%%%%%%%%%%%%
  case 0,
    sizes = simsizes;

    sizes.NumContStates  = 0;
    sizes.NumDiscStates  = 6;
    sizes.NumOutputs     = 1;
    sizes.NumInputs      = 1;
    sizes.DirFeedthrough = 1;
    sizes.NumSampleTimes = 1;   % at least one sample time is needed

    sys = simsizes(sizes);
    
    state=xini;
    for k=1:link
        [state,nextC]=nextState(state,bitsPerHop);
    end
    
    x0  = [state 0]; % State of the register(m=5) and output time hopping unit c
    str = []; ts  = [0 0];

  %%%%%%%%%%%%%%%
  % Derivatives %
  %%%%%%%%%%%%%%%
  case 1,
    sys=[];

  %%%%%%%%%%
  % Update %
  %%%%%%%%%%
  case 2,
      if abs(round(t/Tf)-t/Tf) < 1e-8
          [state,nextC]=nextState(x(1:5),bitsPerHop);
          x(1:5)=state; x(6)=nextC;
      end
      sys=x;
      
  %%%%%%%%%%%
  % Outputs %
  %%%%%%%%%%%
  case 3,
     Ep=1e-3*10^(sigPower/10)*Tf; % Average Pulse Energy
     A=sqrt(Ep);
     tmod=mod(t,Tf);
      
     switch pulseType,
     case 'Gaussian',
        if strcmp(modType,'PPM')
            sys = gaussValue(tmod, A, x(6)*Tc+u*delta+floor(2*tau/Ts)*Ts,tau);
        elseif strcmp(modType,'PAM')
            dhalf=sqrt(3*Ep/(M^2-1));
            sys = gaussValue(tmod, dhalf*(2*u-(M-1)),x(6)*Tc+tau,tau);
         end
     case 'Gaussian 1st Derivative',
         if strcmp(modType,'PPM')
            sys = gauss1stDevValue(tmod, A, x(6)*Tc+u*delta+tau,tau);
         elseif strcmp(modType,'PAM')
            dhalf=sqrt(3*Ep/(M^2-1));
            sys = gauss1stDevValue(tmod, dhalf*(2*u-(M-1)),x(6)*Tc+floor(2*tau/Ts)*Ts,tau);
         end
     case 'Gaussian 2nd Derivative',
         if strcmp(modType,'PPM')
            sys = scholtzValue(tmod, A, x(6)*Tc+u*delta+floor(2*tau/Ts)*Ts,tau);
        elseif strcmp(modType,'PAM')
            dhalf=sqrt(3*Ep/(M^2-1));
            sys = scholtzValue(tmod, dhalf*(2*u-(M-1)),x(6)*Tc+tau,tau);
         end
     case 'Manchester',
         if strcmp(modType,'PPM')
            sys = manchesterValue(tmod, A, x(6)*Tc+u*delta+floor(2*tau/Ts)*Ts,tau);
        elseif strcmp(modType,'PAM')
            dhalf=sqrt(3*Ep/(M^2-1));
            sys = manchesterValue(tmod, dhalf*(2*u-(M-1)),x(6)*Tc+tau,tau);
        end
     case 'Sine',
         if strcmp(modType,'PPM')
            sys = sineValue(tmod, A, x(6)*Tc+u*delta+floor(2*tau/Ts)*Ts,tau);
         elseif strcmp(modType,'PAM')
            dhalf=sqrt(3*Ep/(M^2-1));
            sys = sineValue(tmod, dhalf*(2*u-(M-1)),x(6)*Tc+tau,tau);
         end
     case 'Rectangle',
         if strcmp(modType,'PPM')
            sys = rectangleValue(tmod, A, x(6)*Tc+u*delta+floor(2*tau/Ts)*Ts,tau);
        elseif strcmp(modType,'PAM')
            dhalf=sqrt(3*Ep/(M^2-1));
            sys = rectangleValue(tmod, dhalf*(2*u-(M-1)),x(6)*Tc+tau,tau);
         end
     otherwise
         error('Unsupported Pulse Type');
     end

  %%%%%%%%%%%%%%%%%%%%%%%
  % GetTimeOfNextVarHit %
  %%%%%%%%%%%%%%%%%%%%%%%
  case 4,
      sys=[];

  %%%%%%%%%%%%%
  % Terminate %
  %%%%%%%%%%%%%
  case 9,
     sys=[];
     
  %%%%%%%%%%%%%%%%%%%%
  % Unexpected flags %
  %%%%%%%%%%%%%%%%%%%%
  otherwise
    error(['Unhandled flag = ',num2str(flag)]);

end