dbtex6.m

雷达信号处理、或阵列信号处理中能够用上的重要的matlab工具箱——阵列信号处理工具箱

%DBTEX6 An example doing Monte-Carlo simulations with DML and an ULA.

%
%   *  DBT, A Matlab Toolbox for Radar Signal Processing  *
% (c) FOA 1994-2000. See the file dbtright.m for copyright notice.
%  Start        : 951221 Svante Bj鰎klund (svabj).
%  Latest change: $Date: 2000/10/16 15:39:54 $ $Author: svabj $.
%  $Revision: 1.2 $
% *****************************************************************************

% ----------------------------------------------------------------------- %
% Parameters.
% ----------------------------------------------------------------------- %
lambda   = 0.03;        % wavelength.
D  = 0.45*lambda;    % Element separation.
T  = 35;       % Number of snapshots.
K  = 12;       % Number of digital antenna channels.

theta = d2r([-5 0]);    % Target angles. The number of targets is
            %  given by the number of target angles.
phi   = zeros(size(theta'));  % Target angles.
SNRtrial= [-10 -5 0]';     % Signal to noise ratio in dB at each
            %  antenna element!?!
alpha = d2r([20 210])'; % Start phases of the target signals.
dalpha   = d2r([0 -10])';  % A constant phase shift between snapshots.
            %  Means targets movements at constant velocity.
dist=Inf*ones(size(theta'));  % Distances to the sources.

tgtModel       = 'const';
noiseModel        = 'rndn';

doaStart = d2r([-4 1]);

Ntrial = 10;

% ----------------------------------------------------------------------- %
% Commands.
% ----------------------------------------------------------------------- %

AngleIndexInDoaT = 1;

% Define the antenna.
ant = defant('isotropULA',[K,D]);

Ndoa         = size(doaStart,2);
NSNRtrial    = size(SNRtrial,1);
doaMean      = zeros(NSNRtrial,Ndoa);
doaStdDev    = zeros(NSNRtrial,Ndoa);
doaStdDevCRB = zeros(NSNRtrial,Ndoa);
noTgt      = size(theta,2);

for nSNR =1:NSNRtrial
  fprintf('nSNR = %d\n',nSNR);
  edoaAll = [];
  SNR = ones(size(theta',1),1) * SNRtrial(nSNR,1);
  RssHat    = zeros(noTgt, noTgt);
  for nTrial = 1:Ntrial
    fprintf('  nSNR = %d, nTrial = %d, Total = %d\n', nSNR, nTrial, ...
      (nSNR-1)*Ntrial+nTrial);

    % Generate simulated received antenna signals.
    [sig, tgtSig] = compsim4(ant, lambda, T, tgtModel, ...
      [theta', phi, SNR, alpha, ...
      dalpha, dist, eye(size(theta',1))], noiseModel, eye(K));

    % Estimate the DOA:s
    edoa = sdoapar1('dml',sig, doaStart);
    pdoapar(edoa)
    edoaAll = [ edoaAll; edoa];
    %edoaAll = [ edoaAll; getm(edoa.doa,1,':',':')'];

    % Estimate target signal correlation matrix.
    RssHat = RssHat + (1/T)*tgtSig*tgtSig';

  end%for nTrial
  doaMean(nSNR,:)      = mean(edoaAll);
  doaStdDev(nSNR,:)    = std(edoaAll);
  doaStdDevCRB(nSNR,:) = crbdet(ant, theta, RssHat, T, lambda)
end%for nSNR

fprintf('\nMean of DOA:s [degrees]\n')
fprintf('   DOA 1     DOA2\n')
disp(r2d(doaMean))
fprintf('Standard deviation of of DOA:s [degrees]\n')
fprintf('   DOA 1     DOA2\n')
disp(r2d(doaStdDev))
fprintf('Standard deviation Cramer Rao Bound of of DOA:s [degrees]\n')
fprintf('   DOA 1     DOA2\n')
disp(r2d(doaStdDevCRB))


plot(SNRtrial,r2d(doaStdDev(:,1)), SNRtrial,r2d(doaStdDev(:,2)),  ...
  SNRtrial,r2d(doaStdDevCRB(:,1)))
title('Standard deviation of DOA')
xlabel('SNR')
ylabel('[degrees]')
legend('Target 1', 'Target2', 'CRB')

% printfm dbtex6a.eps [] 12