dfb.m

阵列信号处理的工具箱

function [sigOut,vd] = dfb(sig,prf)

%  function [sigOut,vd] = dfb(sig,prf)
%
%  Doppler filter bank. This function takes the absolute value of the result.
%  Use the function dfb2 if this is not wanted.
%
%  sigOut   RxRadarSigT
%  vd    ?     ?
%  sig      RxRadarSigT
%  prf      RealScalarT : PRF (Pulse Repetition Frequency)
%
%Known Bugs:
%  dfb does not save information about the performed filtering, which
%  is necessary to make high resolution doppler estimation.
%  The frequencies of the doppler channels are not saved in the output signal.
%  This function takes the absolute value of the result.
%  Use the function dfb2 if this is not wanted.
%
%See Also:
%  dfb2

%   *  DBT, A Matlab Toolbox for Radar Signal Processing  *
%  (c) FOA 1994-2000. See the file dbtright.m for copyright notice.
%
%  Start        : 961120 Fredrik Athley (freath).
%  Latest change: $Date: 2000/10/16 15:20:36 $ $Author: svabj $.
%  $Revision: 1.15 $
% *****************************************************************************


disp('Warning: The function dfb is obsolete. Use dfb2 instead.')

ant = sig.antenna;

%lambda = ant.lambda;
waveform = sig.waveform;
lambda  = waveform.wavelength;

K = ant.noElem;
XX =  sig.signals;
s = sizem(XX);

noPulses = s(1);
noRangeBins = s(2);
noBeams = s(3);
noCPIs = s(5);
N = noPulses;
if N>1
  if N~=2^round(log(N)/log(2))
    error('DBT-Error: Number of pulses must be a power of 2')
  end
  YY = zerosm(s);
  for range=1:noRangeBins
    for cpi=1:noCPIs
      X = getm(XX,':',range,':',1,cpi);
      X = reshape(X,noBeams,noPulses);
      Y = abs(fft(X.'))';
      Y = [Y(:,N/2+2:N) Y(:,1:N/2+1)];
      YY = setm(YY,Y.',':',range,':',1,cpi);
    end
  end
  N = s(2);
  fd = linspace(0,(N - 1)/N*prf,N);
  fd = (-(N/2-1):N/2)*prf/N;
  vd = lambda/2*fd;
else
  YY = XX;
end

%sigOut.dataType = 'RxRadarSigT';
%sigOut.antenna = ant;
sigOut = sig;
sigOut.signals = YY;