pulscomp.m

阵列信号处理的工具箱

function [sigOut] = pulscomp(sigIn, pulsecode)

% *****************************************************************************
%   *  DBT, A Matlab Toolbox for Radar Signal Processing  *
% (c) FOA 1994-2000. See the file dbtright.m for copyright notice.
%
%  function [sigOut] = pulscomp(sigIn, pulsecode)
%
%  Performs pulse compression.
%
%  After the execution of this function, targets in range bin 1 is located
%  in element number (length of pulse code) in the output signal matrix.
%
%  sigOut (RxRadarSigT): Output (pulse compressed) radar signal.
%  sigIn (RxRadarSigT): Input radar signal.
%  pulsecode (CxVectorT): Pulse code to use, e.g. Barker 13old =
%    [1 -1 1 -1 1 1 -1 -1 1 1 1 1 1].'
%
%Known Bugs:
%  pulscomp does not save information about the performed filtering, which
%  is necessary to make high resolution range estimation.

%
%  Start        : 961120 Fredrik Athley (freath).
%  Latest change: $Date: 2000/10/16 15:21:26 $ $Author: svabj $.
%  $Revision: 1.23 $
% *****************************************************************************

%Possible changes of the code:
%  Remove "if (size(x,2) > 1)" and use getm3 instead of getm.
%  Move "conj(fliplr" outside the loop.

%ant = sigIn.antenna;
XX =  sigIn.signals;
s = sizem(XX);
if nargin<2
  disp(' ')
  disp('No pulse code specified.')
  disp('Using default pulse code: Barker 13')
  disp(' ')
  pulsecode = [1 -1 1 -1 1 1 -1 -1 1 1 1 1 1].'; % Barker 13 pulsecode
end

if (size(pulsecode,2) > 1)
  disp('Warning: In pulscomp, "pulsecode" is transposed. The filtering will not give right result.')
end;


noPulses    = s(1);
noRangeBins = s(2);
noBeams     = s(3);
noNotUsed   = s(4);
noCPIs      = s(5);
noTrials    = s(6);

if noRangeBins<length(pulsecode)
  fprintf('\nWarning: Cannot perform pulse compression. Number of range bins is less than the length of the pulsecode. Returning the signal unprocessed.\n\n')
  sigOut =sigIn;
else
  % N = min(2*15+3,NO_OF_RANGEBINS);
  %y = zeros(1,noRangeBins);	% What for is this call to "zeros" ?
  YY = zerosm(s);
  filterCoeffs = conj(fliplr(pulsecode.'));
  %filterCoeffs = filterCoeffs ./ norm(filterCoeffs);

  for trialLoop = 1:noTrials
  for cpiLoop = 1:noCPIs
  for notUsedLoop = 1:noNotUsed
  for beam = 1:noBeams
    for pulse=1:noPulses
      %fprintf('beam=%d (%d), pulse=%d\n',beam,noBeams,pulse)
      %x = getm(XX,pulse,':',beam,notUsedLoop,cpiLoop,trialLoop);
      %x2 = getm3(XX,2,[],pulse,':',beam,notUsedLoop,cpiLoop,trialLoop);
      x = XX(pulse,':',beam,notUsedLoop,cpiLoop,trialLoop).';
      %x4 = getm4(XX,pulse,':',beam,notUsedLoop,cpiLoop,trialLoop);

if(0)
      difference = sum(sum(abs(x - x3)));
      %limit = 0.5*size(x,1)*size(x,2)*eps;
      limit = 0;
      if (difference > limit)
        difference
        error('Difference to large.')
      else
        %disp('  Test Ok.')
      end%if
end%if(0)

      if (size(x,2) > 1)
        error('DBT-Error: In pulscomp, "x" is transposed.')
        %disp('Warning: In pulscomp, "x" is transposed. The filtering will not give right result.')
      end%if
      y = filter(filterCoeffs,1,x.');
      %YY = setm(YY,y,pulse,':',beam,notUsedLoop,cpiLoop,trialLoop);
      YY(pulse,':',beam,notUsedLoop,cpiLoop,trialLoop) = y;	% setm
    end%for pulse
    infoStr = sprintf('pulscomp: cpi = %d(%d), beam = %d(%d)\r',cpiLoop, ...
      noCPIs, beam,noBeams);
    dbtinfo(infoStr,1);
  end%for beam
  end%for notUsedLoop
  end%for cpiLoop
  dbtinfo('');	%New line.
  end%for trialLoop

  %sigOut.dataType = 'RxRadarSigT';
  %sigOut.antenna = ant;
  sigOut = sigIn;
  sigOut.signals = YY;
end%if