integratedemod.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] = IntegrateDemod(t,x,u,flag,Tf,M,Ns,Np,Ts)

global ACQUISITION_ON;
global DATA_ON DATA_ON DATA_ON_STATE_TIME;

switch flag,

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

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

    sys = simsizes(sizes);
    
    x0  = zeros(M+1,1); % subtotal, number of pulses observed, number of try
    str = []; ts  = [0 0];

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

  %%%%%%%%%%
  % Update %
  %%%%%%%%%%
  case 2,
      if DATA_ON>0 & abs(t/(DATA_ON_STATE_TIME+Ts)-1) < 1e-8
          if DATA_ON==1
              DATA_ON=2;
              x(1:M)=zeros(M,1); x(M+1)=0;
          elseif DATA_ON==2
              [Y,Index]=max(x(1:M)); x(M+1)=Index-1;
              x(1:M)=zeros(M,1);
          end
      elseif DATA_ON>0 & abs(round((t-DATA_ON_STATE_TIME)/Tf) - (t-DATA_ON_STATE_TIME)/Tf ) < 1e-8 & abs(t/DATA_ON_STATE_TIME-1) >1e-8
          if mod(round((t-DATA_ON_STATE_TIME)/Tf),Ns)==0 & round((t-DATA_ON_STATE_TIME)/Tf)+Ns<Np
              [Y,Index]=max(x(1:M)); x(M+1)=Index-1;
              x(1:M)=zeros(M,1);
          end
      elseif DATA_ON==0
          x(M+1)=0;
      end
      x(1:M)=x(1:M)+u(1)*u(2:M+1)*Ts;
      sys=x;
      
  %%%%%%%%%%%
  % Outputs %
  %%%%%%%%%%%
  case 3,
      if DATA_ON>0
          sys=x(M+1);
      end
      
  %%%%%%%%%%%%%%%%%%%%%%%
  % GetTimeOfNextVarHit %
  %%%%%%%%%%%%%%%%%%%%%%%
  case 4,
      sys=[];

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

end