s_xmp3.m

线性调频信号通过匹配滤波器的程序 还有一些simulink仿真模型

function [sys,x0,str,ts] = s_xmp3(t,x,u,flag,Kp,Ki,Kd, ...
                                  L_upper,L_lower,T_samp)
%   S-file example 3
%   MATLAB S-file implementation of discrete PID controller.
%
%   Based on sfuntmpl.m, supplied with SIMULINK
%   Copyright (c) 1990-96 by The MathWorks, Inc.
%
M=1;m=1;l=1;
switch flag,      
  case 0,                % Initialization
    [sys,x0,str,ts]=mdlInitializeSizes(T_samp) ;
  case 1,                % Compute derivatives of continuous states
    sys=mdlDerivatives(t,x,u) ;
  case 2,
    sys=mdlUpdate(t,x,u,L_upper,L_lower,T_samp);
  case 3,
    sys=mdlOutputs(t,x,u,Kp,Ki,Kd,T_samp);  % Compute output vector
  case 4,                   % Compute time of next sample
    sys=mdlGetTimeOfNextVarHit(t,x,u);
  case 9,                   % Finished. Do any needed 
    sys=mdlTerminate(t,x,u);
  otherwise                 % Invalid input
    error(['Unhandled flag = ',num2str(flag)]);
end

%********************************************************
%*                    mdlInitializeSizes                *
%********************************************************
function [sys,x0,str,ts]=mdlInitializeSizes(T_samp)
% Return the sizes of the system vectors, initial 
% conditions, and the sample times and offets.
sizes = simsizes;   % Create the sizes structure
sizes.NumContStates  = 0;
sizes.NumDiscStates  = 1;
sizes.NumOutputs     = 1;
sizes.NumInputs      = 1;
sizes.DirFeedthrough = 1;
sizes.NumSampleTimes = 1;   
sys = simsizes(sizes);      % load sys with sizes structure
x0  = [0];    % Specify initial conditions for all states 
str = [];     % str is always an empty matrix
ts  = [T_samp 0]; %initialize the array of sample times
set_param(gcb,'UserData',0) ;


%********************************************************
%*                    mdlDerivatives                    *
%********************************************************
function sys=mdlDerivatives(t,x,u,M,m,l)
% Compute derivatives of continuous states
sys = [];

%********************************************************
%*                    mdlUpdate                         *
%********************************************************
function sys=mdlUpdate(t,x,u,L_upper,L_lower,T_samp)
% Compute update for discrete states. If necessary, check 
% for sample time hits.
x_new = [x(1) + T_samp*u(1)] ;
x_new = min(max(x_new,L_lower),L_upper) ; % Prevent wind-up
sys = x_new ;

%********************************************************
%*                    mdlOutputs                        *
%********************************************************
function sys=mdlOutputs(t,x,u,Kp,Ki,Kd,T_samp)
% Compute output vector given current state, time, input
u_prev = get_param(gcb,'UserData') ;
set_param(gcb,'UserData',u(1)) ;     % Get input at 
                                     % previous sample
u_deriv = (u(1) - u_prev)/T_samp ;   % Save current input
sys = Kp*u(1) + Ki*x(1) + Kd*u_deriv ;

%********************************************************
%*                    mdlGetTimeOfNextVarHit            *
%********************************************************
function sys=mdlGetTimeOfNextVarHit(t,x,u)
% Return the time of the next hit for this block. 
sys = [] ;

%********************************************************
%*                    mdlTerminate                      *
%********************************************************
function sys=mdlTerminate(t,x,u)
% Perform any necessary tasks at the end of the simulation
sys = [];