uwbppmdatasource.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] = UWBPPMDataSource(t,x,u,flag,sigPower,tau,Tf,Tc,delta,M,link,xini,dataOnState,bitsPerHop,Ns,Np,Ts)

global ACQUISITION_ON;

switch flag,

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

    sizes.NumContStates  = 0;
    sizes.NumDiscStates  = 10;
    sizes.NumOutputs     = 2;
    sizes.NumInputs      = 0;
    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 0 0 0 0]; % State of the register(m=5), output time hopping unit c, data on flag
    str = []; ts  = [0 0];

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

  %%%%%%%%%%
  % Update %
  %%%%%%%%%%
  case 2,
      if abs(round(t/Tf)-t/Tf) < 1e-8
          if ACQUISITION_ON==0
              x(7)=0;
          end
          [state,nextC]=nextState(x(1:5),bitsPerHop);
          x(1:5)=state; x(6)=nextC;
          if state==dataOnState'
              x(7)=1; %Data On Flag
              x(8)=t; %Data On State Time
              x(10)=floor(rand(1)*M);
          elseif x(7)==1 & mod(round((t-x(8))/Tf),Ns)==0 & round((t-x(8))/Tf)+Ns<Np
              x(10)=floor(rand(1)*M);
          end    
      end
      sys=x;
      
  %%%%%%%%%%%
  % Outputs %
  %%%%%%%%%%%
  case 3,
     Ep=1e-3*10^(sigPower/10)*Tf; % Average Pulse Energy
     A=sqrt(Ep);
     tmod=mod(t,Tf);
     if ACQUISITION_ON>0 & x(7)==1
         data = x(10);
         output = scholtzValue(tmod, A, x(6)*Tc+x(10)*delta+floor(2*tau/Ts)*Ts,tau);
         sys=[data output];
     else
         sys = [0 0];
     end

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

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

end