smlfun.m

阵列信号处理的工具箱

function [output, Rss, sigma2] = smlfun(theta,Rhat,antenna,lambda)

%SMLFUN Calculates the optimization criterion , source correlation matrix and noise power for SML.
%
%--------
%Synopsis:
%  [output, Rss, sigma2] = smlfun(theta,Rhat,antenna,lambda)
%
%Description:
%  Calculates the optimization criterion , source correlation matrix
%  and noise power for Stochastic Maximum Likelihood (SML). See reference
%  [2] p. 109-111 for details.
%
%Output and Input:
%  output (): The criterion to minimize.
%  Rss (RxMatrixT): Estimated source signal correlation matrix.
%  sigma2 (RealScalarT): Estimated noise power.
%
%  theta (DoaT): DOA of source signals.
%  Rhat (CxMatrixT): Estimated antenna signal correlation matrix.
%  antenna (): Antenna definition.
%  lambda (): Wavelength [m].
%
%--------
%Notations:
%  Data type names are shown in parentheses and they start with a capital
%  letter and end with a capital T. Data type definitions can be found in [1]
%  or by "help dbtdata".
%  [D] = This parameter can be omitted and then a default value is used.
%  When the [D]-input parameter is not the last used in the call, it must be
%  given the value [], i.e. an empty matrix.
%  ... = There can be more parameters. They are explained under respective
%  metod or choice.
%
%Examples:
%
%Software Quality:
%  (About what is done to ascertain software quality. What tests are done.)
%  The methods 'dml', 'sml', 'wsf', 'ssf', 'rmusic' and 'esprit' were used
%  in the work done by A. Heydarkhan [8].
%  The method 'ptmf' was used in the work done by M. Borgstr鰉 and
%  S. Bj鰎klund [9].
%
%Known Bugs:
%
%References:
%  [1]: Bj鰎klund S.:"DBT, A MATLAB Toolbox for Radar Signal Processing.
%    Reference Guide", FOA-D--9x-00xxx-408--SE, To be published.
%  [2]: Haykin S., Litva J., Shepherd T.J.(Eds.):"Radar Array Processing",
%    Springer Verlag 1993, ISBN 3-540-55224-3, 0-387-55224-3.
%
%See Also:
%  doapar1

%   *  DBT, A Matlab Toolbox for Radar Signal Processing  *
% (c) FOA 1994-2000. See the file dbtright.m for copyright notice.
%  Start        : 970729 Amir Heydarkhan (amihey).
%  Latest change: $Date: 2000/10/16 15:21:57 $ $Author: svabj $.
%  $Revision: 1.10 $
% *****************************************************************************

m = size(Rhat,1);
d = length(theta);
%lambda = antenna.lambda;
A = spastemat(antenna, theta', lambda);
Ac = inv(A'*A)*A';
p = eye(m)-A*Ac;
sigma2 = 1/(m-d)*trace(p*Rhat);
Psml = Ac*(Rhat-sigma2*eye(m))*Ac';
output = log10(det(A*Psml*A'+sigma2*eye(m)));
output = real(output);

if (nargout > 1)
   Rss =  Psml;
   sigma2 = sigma2;
end%if