pilottemplategen.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] = PilotTemplateGen(t,x,u,flag,tau,Tf,Tc,xini,bitsPerHop,Np,Ts)

global UWB_SIG_DETECT_ON UWB_SIG_DETECT_TIME;
global ACQUISITION_ON;
global NEXT_PULSE_TIME;
global NEXT_HOPPING_ON;
global INTEGRATION_START_TIME;
global ACQ_FRAME_TIME ACQ_REGISTER_STATE;


switch flag,

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

    sizes.NumContStates  = 0;
    sizes.NumDiscStates  = 9+Np;
    sizes.NumOutputs     = 1;
    sizes.NumInputs      = 0;
    sizes.DirFeedthrough = 0;
    sizes.NumSampleTimes = 1;   % at least one sample time is needed

    sys = simsizes(sizes);
    
    code=pilotHoppingCode(xini,bitsPerHop,Np);
    x0  = [0 0 zeros(1,7) code]; % Number of Present Code, Number of try, Time hopping codes c
    str = []; ts  = [0 0];
    
    NEXT_PULSE_TIME=-1;
    NEXT_HOPPING_ON=0;
    INTEGRATION_START_TIME=-1;
    ACQ_FRAME_TIME=-1;
    ACQ_REGISTER_STATE=[0 0 0 0 0];

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

  %%%%%%%%%%
  % Update %
  %%%%%%%%%%
  case 2,
      
      if UWB_SIG_DETECT_ON==1
          UWB_SIG_DETECT_ON=2;
          x(2)=1; % 1st Try
          x(1)=1;
          sys=x;
          presentC=x(10+0); nextC=x(10+1);
          NEXT_PULSE_TIME=UWB_SIG_DETECT_TIME+(nextC-presentC)*Tc+Tf;
          INTEGRATION_START_TIME=NEXT_PULSE_TIME-floor(2*tau/Ts)*Ts;
      end
      
      time2Change=NEXT_PULSE_TIME+floor(2*tau/Ts)*Ts+Ts;
      if UWB_SIG_DETECT_ON>1 & abs(t/time2Change-1) < 1e-8
          if ACQUISITION_ON==0 & NEXT_HOPPING_ON==1
              NEXT_HOPPING_ON=0;
              x(2)=x(2)+1;
              frameStartTime=UWB_SIG_DETECT_TIME-x(10+x(2)-1)*Tc-floor(2*tau/Ts)*Ts;
              numFrame=floor((t-frameStartTime)/Tf);
              netNumFrame=mod(numFrame,Np);
              x(1)=mod(x(2)-1+netNumFrame,Np);
              nextPulseTime=frameStartTime+numFrame*Tf+x(10+x(1))*Tc+floor(2*tau/Ts)*Ts;
              if nextPulseTime<t+floor(2*tau/Ts)*Ts
                  x(1)=mod(x(1)+1,Np);
                  nextPulseTime=frameStartTime+(numFrame+1)*Tf+x(10+x(1))*Tc+floor(2*tau/Ts)*Ts;
              end
              NEXT_PULSE_TIME=nextPulseTime;              
              INTEGRATION_START_TIME=nextPulseTime-floor(2*tau/Ts)*Ts;
          else
              presentC=x(10+x(1));
              x(1)=mod(x(1)+1,Np);
              nextC=x(10+x(1));
              NEXT_PULSE_TIME=NEXT_PULSE_TIME+(nextC-presentC)*Tc+Tf;
              if ACQUISITION_ON==1
                  ACQUISITION_ON=2;
                  ACQ_FRAME_TIME=NEXT_PULSE_TIME-nextC*Tc-floor(2*tau/Ts)*Ts;
                  ACQ_REGISTER_STATE=findState(mod(x(1)-1,Np),xini,bitsPerHop);
                  if ACQ_FRAME_TIME < t
                      disp('error');
                      ACQ_FRAME_TIME=ACQ_FRAME_TIME+Tf;
                      ACQ_REGISTER_STATE=findState(mod(x(1)+1,Np),xini,bitsPerHop);
                  end
                  fprintf('Acquired Frame Time=%5.3f ns\n',ACQ_FRAME_TIME*1e9);
              end
              if ACQUISITION_ON==2
                  ACQUISITION_ON=3;
                  INTEGRATION_START_TIME=NEXT_PULSE_TIME-floor(2*tau/Ts)*Ts;
              end
          end
          sys=x;
      else
          sys=x;
      end

  %%%%%%%%%%%
  % Outputs %
  %%%%%%%%%%%
  case 3,
      if UWB_SIG_DETECT_ON>1
          pulseTimeBegin=NEXT_PULSE_TIME-floor(2*tau/Ts)*Ts;
          pulseTimeEnd=NEXT_PULSE_TIME+floor(2*tau/Ts)*Ts;
          if (t>pulseTimeBegin & t<pulseTimeEnd) |...
              abs(t/pulseTimeBegin-1) < 1e-8 | abs(t/pulseTimeEnd-1) < 1e-8
              sys = scholtzValue(t-NEXT_PULSE_TIME, 1, 0, tau);
          else
              sys=0;
          end
      else
          sys=0;
      end
      
  %%%%%%%%%%%%%%%%%%%%%%%
  % GetTimeOfNextVarHit %
  %%%%%%%%%%%%%%%%%%%%%%%
  case 4,
      sys=[];

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

end