calcfiltinit.m

阵列信号处理的工具箱

arginNo = arginNo +1;
if (nargin < arginNo)
  orthBeamFlag = [];
end
arginNo = arginNo +1;
if (nargin < arginNo)
  extraParam = [];
end
arginNo = arginNo +1;
if (nargin < arginNo)
  normType = [];
end
arginNo = arginNo +1;


% ****************** Default values ******************

sigVectLen = sizeSigIn(1);
noSamples = sizeSigIn(2);

if isempty(taperCoeff)
  taperCoeff = ones(sigVectLen,1);
  taperCoeff = [];
end%if
if isempty(interCorrMat)
  %interCorrMat = eye(sigVectLen);
  interCorrMat = [];
end%if
if isempty(orthBeamFlag)
  orthBeamFlag = 0;
end%if
if isempty(extraParam)
  extraParam = [];
end%if
if isempty(normType)
  normType = 'noNorm';
end%if


% ************* Pick out some more fields from input parameters. *************



% ****************** Error check input parameters ******************

%chkdtype(sigMatIn, 'CxMatrixT')
chkdtype(method, 'StringT')
chkdtype(steMat, 'CxMatrixT')
chkdtype(taperCoeff, 'CxVectorT')
chkdtype(interCorrMat, 'CxMatrixT', 'EmptyT')

% ----------------------------------------------------------------------- %
% Loops for several range gates and trials.
% ----------------------------------------------------------------------- %

% ****************** Create output variable. ******************

basisMat = eye(sigVectLen);




    % ----------------------------------------------------------------------- %
    % Code common to all methods.
    % ----------------------------------------------------------------------- %

    % **************** Pick out fields from input parameters. ****************


    % ****************** Precalculations. ******************

    if (strcmp(method,'cbf') | strcmp(method,'acbf'))
      method = 'atfir';
    end%if

    if (strcmp(method,'conv') | strcmp(method,'aconv'))
      method = 'atfir';
    end%if

    % ----------------------------------------------------------------------- %
    % Methods
    % ----------------------------------------------------------------------- %

    % ----------------------------------------------------------------------- %
    % Adaptive Total Finite Response Filter (Adaptive Conventional Beamforming)
    %
    % Start: 981013 Svante Bj鰎klund (svabj).
    % ----------------------------------------------------------------------- %
    if (strcmp(method,'atfir'))
      aModel = steMat;
        % The signal according to the used signal model.
 
      sd = dotapering(aModel, taperCoeff);
        % Desired responses including tapering.

      if (~isempty(interCorrMat))
        W = inv(interCorrMat) * sd;
          % Filtering weights including side lobe cancellation.
      else
        W = sd;
      end%if

      if (orthBeamFlag), W = orthbeam(W); end%if
      basisMat =  W;
      weightMatrix = basisMat;
      %freqPos = ...


    % ----------------------------------------------------------------------- %
    % Total Finite Response Filter (Conventional beamforming).
    %
    % Start: 98xxxx NN NN (uuuu).
    % ----------------------------------------------------------------------- %
    elseif (strcmp(method,'tfir'))


    % ----------------------------------------------------------------------- %
    % Capons Method.
    %
    % Start: 981013 Svante Bj鰎klund (svabj).
    % ----------------------------------------------------------------------- %
    elseif (strcmp(method,'capon'))
      basisMat =  steMat;
      weightMatrix = basisMat;
      %freqPos = ...


    % ----------------------------------------------------------------------- %
    % Generalized Constrained Adaptive Array Processor ([2] p. 355).
    %
    % Start: 981122 Svante Bj鰎klund (svabj).
    % ----------------------------------------------------------------------- %
    elseif (strcmp(method,'gcaap'))
      if isempty(extraParam)
        extraParam = [];	% Should be a suitable default value.
      end%if
      ConstraintMatrix = extraParam{1};
      ConstraintValues = extraParam{2};
      % W = ...

if (0)
      sigCorrMat = (1/noSamples) * sigMatIn*sigMatIn';
      invSigCorrMat = inv(sigCorrMat);
      normFactors = 1 ./ diag(steMat' * invSigCorrMat * steMat);
      W = (invSigCorrMat * steMat) * diag(normFactors);
      if (orthBeamFlag), W = orthbeam(W); end%if
      %sigMatOut = W' * sigMatIn;
      basisMat =  W;
      weightMatrix = basisMat;
      %freqPos = ...
end%if (0)


    % ----------------------------------------------------------------------- %
    % Discrete Fourier Transform Method.
    %
    % Start: 981013 Svante Bj鰎klund (svabj).
    % ----------------------------------------------------------------------- %
    elseif (strcmp(method,'fft'))
      if isempty(extraParam)
        extraParam = sigVectLen;
      end%if
      noPulses = sigVectLen;
      noDopChan = extraParam;

      basisMat =  fftshift1(dftopm(noDopChan,noPulses)');
      weightMatrix = basisMat;
      %freqPos = ...


    % ----------------------------------------------------------------------- %
    % Inverse Discrete Fourier Transform Method.
    %
    % The implementation is not finnished.
    %
    % Start: 98xxxx Svante Bj鰎klund (svabj).
    % ----------------------------------------------------------------------- %
    elseif (strcmp(method,'ifft'))
      if isempty(extraParam)
        extraParam = sigVectLen;
      end%if
      noPulses = extraParam;
      noDopChan = sigVectLen;

      if (0) %Most is done in "calcfiltproc".
        if isempty(extraParam)
          extraParam = size(sigMatIn,1);
        end%if
        noPulses = extraParam;
        noDopChan = size(sigMatIn,1);
        sigMatIn = diag(taperCoeff) * sigMatIn;
        % The beams in IFFT are always orthogonal. No need for an explicit
        % orthogonalization.
        sigMatOut = fftshift1(ifft(sigMatIn, noPulses),'inv');
      end%if (0)

      %basisMat =  fftshift1(dftopm(noDopChan,noPulses)');
        % The inverse discrete Fourier transform matrix should be 
        % Bi = conj(dftopm(N,N))/N, see function "dftopm".
      weightMatrix = basisMat;
      %freqPos = ...


    % ----------------------------------------------------------------------- %
    % Direct Transformation Matrix Method.
    % (Direct beamforming weight multiplication)
    %
    % Start: 981013 Svante Bj鰎klund (svabj).
    % ----------------------------------------------------------------------- %
    elseif (strcmp(method,'trans'))
      if (0)
        transMat = steMat;
        sigMatIn = diag(taperCoeff) * sigMatIn;  % Shouldn't it be "transMat"
          % instead of "sigMatIn" ?
        if (orthBeamFlag), transMat = orthbeam(transMat); end%if
        sigMatOut = transMat' * sigMatIn;
      end%if (0)

      basisMat =  steMat;
      weightMatrix = basisMat;
      %freqPos = ...


  
    % ----------------------------------------------------------------------- %
    % SB Interference Eigenvector Method.
    % (Using the eigenvectors as weights)
    %
    % Implementation is not finnished.
    %
    % Start: 991017 Svante Bj鰎klund (svabj).
    % ----------------------------------------------------------------------- %
    elseif (strcmp(method,'intereigvec'))
      [U,S,V]=svd(interCorrMat);
        % Eigendecomp. of correlation matrix using SVD.
      basisMat =  U;
      weightMatrix = basisMat;
      %freqPos = ...



    % ----------------------------------------------------------------------- %
    % SB Data Eigenvector Method.
    % (Using the eigenvectors as weights)
    %
    % Implementation is not finnished.
    %
    % Start: 991017 Svante Bj鰎klund (svabj).
    % ----------------------------------------------------------------------- %
    elseif (strcmp(method,'dataeigvec'))
        % The calculation is the same as in 'intereigvec' but the correlation 
        % matrix is formed from the signal samples in "calcfiltproc".
        % This beamforming should result in beams formed in that way that the 
        % eigenvalues of the correlation matrix is the power received through
        % the beams.
      basisMat =  steMat;
      weightMatrix = basisMat;
      %freqPos = ...



    % ----------------------------------------------------------------------- %
    % MUSIC.
    % 
    % Note, this method is non-linear. Other linear processing cannot be 
    % performed after this method. This method should be in the function 
    % "calcspcproc" instead.
    %
    % Start: 990307 Svante Bj鰎klund (svabj).
    % ----------------------------------------------------------------------- %
    elseif (strcmp(method,'music'))
      basisMat =  steMat;
      weightMatrix = basisMat;
      %freqPos = ...



    % ----------------------------------------------------------------------- %
    %
    % ----------------------------------------------------------------------- %
    elseif (strcmp(method,'dummy'))


    % ----------------------------------------------------------------------- %
    % The else branch.
    % ----------------------------------------------------------------------- %
    else
      fprintf('Selected filter method = %s.\n',method)
      error('DBT-Error: Selected filter method is not implemented.')
    end%if



    % ----------------------------------------------------------------------- %
    % Normalization of the weights.
    % ----------------------------------------------------------------------- %

    if (strcmp(normType,'noNorm'))
	% Do nothing.
    elseif (strcmp(normType,'someNorm'))
      %normOfWeights = 
      %weightMatrix = (1/normOfWeights) * weightMatrix;

    else
      fprintf('Selected normalization type = %s.\n',normType)
      error('DBT-Error: Selected normalization type is not implemented.')
    end%if



    % ----------------------------------------------------------------------- %
    % Return data.
    % ----------------------------------------------------------------------- %

methodCalc = method;
freqPos = [];

%endfunction calcfiltinit


function matrixOut = dotapering(matrixIn, taperCoeff)
  if (~isempty(taperCoeff))
    if (issparse(matrixIn))
       lenTap = length(taperCoeff);
       taperCoeffMatrix = spdiags(taperCoeff, 0, lenTap, lenTap);
    else
       taperCoeffMatrix = diag(taperCoeff);
    end%if
    matrixOut = taperCoeffMatrix * matrixIn;
  else
    matrixOut = matrixIn;
  end%if
%endfunction dotapering