compsim5.m

阵列信号处理的工具箱

function sigvar = compsim5(antenna, waveform, noPulses, noRangeBins,targetType, targetParameters, noiseType, noiseParameters, clutterType, clutterParameters)

%  function sigvar = compsim5(antenna, waveform, noPulses, noRangeBins,
%                             targetType, targetParameters, noiseType,
%                             noiseParameters, clutterType, clutterParameters)
%
%  Simulates received antenna signals in active mode (radar).
%  There can be several range bins. A Barker 13 modulation code is used.
%  All the targets are located in range bin 1, which after pulse compression
%  becomes range bin 13.
%  The target, noise and clutter signals are summed to form the output signal.
%
%  The testing of this function is not finnished.
%
%  sigvar         (RxCompSigT)
%  antenna        (AntDefT)
%  waveform       (WaveformT or RealScalarT): Waveform, including wavelength,
%    number of range bins, number of pulses, modulation within a pulse etc.
%    If of data type RealScalarT it is the wavelength (lambda) [m].
%  noPulses       (IntScalarT)  : Number of snapshots.
%  noRangeBins    (IntScalarT   : Number of range bins.
%  targetType     (StringT)     : Target type, se below.
%  targetParameters  Type and contents depends on targetType, see below.
%  noiseType      (StringT)     : Noise type, se below.
%  noiseParameters   Type and contents depends on noiseType, see below.
%  clutterType    (StringT)     : Clutter type, se below.
%  clutterParameters Type and contents depends on clutterType, see below.
%
%  targetType =
%    'const'  : Constant source signals.
%      targetParameters (Matrix = [theta, phi, SNR, alpha, dalpha, dist]
%      theta        (RealVectorT) : Target directions (radians).
%      phi          (RealVectorT) : Target directions (radians). Unused.
%      SNR          (RealVectorT) : Target SNRs [dB].
%      alpha        (RealVectorT) : Target start phases [radians].
%      dalpha       (RealVectorT) : Target phase shifts (doppler shifts) 
%                                   [radians].
%      dist          (RealVectorT): Target distances [m]. This is used as
%                                   the focusing distance when calculating
%                                   the spatial steering vectors. The targets
%                                   are always located in range bin 1 (see 
%                                   above).
%    'rndnw'    : Complex gaussian random source signals. Uncorrelated between
%        targets and in time.
%      targetParameters (Matrix) = [theta, phi, SNR, alpha, dalpha, dist]
%        Parameters theta, phi, dalpha, dist as for 'const'. The other
%          parameters are unused.
%    'rndn'   : Complex gaussian random source signals.
%      targetParameters (Matrix) = [theta, phi, SNR, alpha, dalpha, dist,
%        tgtCorrMat]
%      Parameters theta, phi, dalpha, dist as for 'const'. The other
%        parameters are unused.
%      tgtCorrMat (CxMatrix)  : Source correlation matrix.
%    'notgt'  : No target signals.
%
%  noiseType =
%    'rndnw'  : Complex gaussian noise. Uncorrelated between channels and
%     in time.
%    'nonoise': No noise.

% *****************************************************************************
%   *  DBT, A Matlab Toolbox for Radar Signal Processing  *
% (c) FOA 1994-2000. See the file dbtright.m for copyright notice.
%
%
%  Start        : 951220 Svante Bj鰎klund (svabj).
%  Latest change: $Date: 2000/10/16 15:20:13 $ $Author: svabj $.
%  $Revision: 1.13 $
% *****************************************************************************

% Sample time also as input parameter!?! Waveform or PRI also ?

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

chkdtype(antenna, 'AntDefT')
chkdtype(noPulses, 'IntScalarT')
chkdtype(targetType, 'StringT')
chkdtype(noiseType, 'StringT')

noElem =      antenna.noElem;

if (isstruct(waveform))
  lambda = waveform.wavelength;
else
  % Allows a simplified call.
  lambda = waveform;
end%if


if (strcmp(noiseType,'nonoise'))
  sammansattning = 2;
elseif (strcmp(targetType,'notgt'))
  sammansattning = 3;
elseif (strcmp(noiseType,'nonoise') & strcmp(targetType,'notgt'))
  error('DBT-Error: Illegal combination of source and noise signals.')
else
  sammansattning = 1;
end%if

% ------------------- Target signals ------------------------
if (~strcmp(targetType,'notgt'))

%D =      antenna.distElem;
T =      noPulses;

M =      size(targetParameters,1);  % Number of targets.
theta =  targetParameters(:,1);     % Target directions (radians).
%phi =      targetParameters(:,2);     % Target directions (radians).
SNR =       targetParameters(:,3);     % SNR for each target [dB].
alpha =  targetParameters(:,4);     % Phase at the first antenna
                  %  element for each target [radians].
dalpha =    targetParameters(:,5);     % Phase increment for each
                  %  target (doppler shift).
dist =      targetParameters(:,6);
% tgtRangeBins =  rem(round(dist./75),250);

if (size(targetParameters,2) > 6)
  tgtCorrMat =    targetParameters(:,7:(7-1+size(targetParameters,1)));
end

% ----------------------------------------------------------------------- %
% Simulate the signals.
% ----------------------------------------------------------------------- %

if (nargin > 8)
  error('DBT-Error: Clutter is not implemented.')
end%if




% M錶signaler.
% B(m,n) 鋜 en matris med amplitud och fas hos m錶signalerna vid ena 鋘den
% av gruppantennen.
% m 鋜 m錶index och n tidsindex. (m 鋜 radindex och n kolumnindex i matrisen)

% Bilda en m錶signalmatris.
M = size(theta,1);   % Antal m錶.
if (strcmp(targetType,'const'))
  Alpha = zeros(M,T);
  for t=1:T
    Alpha(:,t) = alpha;
  end%for t
  SNRdet  = 10.^(SNR./20);
  SNRdet = copycol(SNRdet,T);
  B =  SNRdet.*ones(M,T).*exp(j*Alpha);
elseif (strcmp(targetType,'rndnw'))
  sigmab = sqrt(0.5)*10.^(SNR./20);    % Source standard deviation.
  sigmab = copycol(sigmab,T);
  B = sigmab.*(randn(M,T) + j*randn(M,T));
elseif (strcmp(targetType,'rndn')) % This part is from the FOA SASP course 96.
  if (size(tgtCorrMat,2) < size(targetParameters,1))
    error('DBT-Error: Missing source correlation matrix.')
  end
  M = size(theta,1);
  [U,S,V] = svd(tgtCorrMat);
  B=(1/sqrt(2))*U*sqrt(S)*(randn(M,T) + j*randn(M,T));
elseif (strcmp(targetType,'notgt'))
  % Do nothing.
else
  error('DBT-Error: The source model does not exist.')
end%if


% Ordna konstant fasskift mellan tidssamplena. Simulates dopples shift due to movement.
Bskift   = zeros(M,T);
for t=1:T
  Bskift(:,t) =exp(j*dalpha*(t-1));
end%for t
B = B.*Bskift;

% % (Antenna element (and subarray) effects. )% Removed. Is part of spastemat.

A = spastemat(antenna,theta',lambda,dist);

end%if ~notgt

% ------------------- Noise signals ------------------------

% Brussignaler.
% Nt(m,n) inneh錶ler komplext brus. m 鋜 antennelementindex. n 鋜 tidsindex.
if (strcmp(noiseType,'rndnw'))
  sigman = sqrt(0.5);         % Noise standard deviation.
  NNt = zerosm([noPulses,noRangeBins,noElem,1,1]);
  for k=1:noRangeBins
    Nt   = sigman*(randn(noElem,noPulses) + j*randn(noElem,noPulses));
    NNt = setm(NNt,Nt',':',k,':',1,1);
  end
elseif (strcmp(noiseType,'nonoise'))
  NNt = zerosm([noPulses,noRangeBins,noElem,1,1]);
else
  error('DBT-Error: The noise model does not exist.')
end%if


if (~(isstruct(waveform)))
    pulsecode = [1 -1 1 -1 1 1 -1 -1 1 1 1 1 1]; % Barker 13 pulsecode
  else
    pulsecode = waveform.pModulation.';
end%if



% Mottagna signaler fr錸 antennelementen.
% XX(m,n,p,1,1) inneh錶ler mottagna signaler fr錸 antennelementen.
% m 鋜 pulsindex. n 鋜 avst錸dsindex, p 鋜 kanalindex
XX = zerosm([noPulses,noRangeBins,noElem,1,1]);
L = length(pulsecode);
if noRangeBins<L
  disp('Number of range bins is less than the length of the pulse code')
  disp('No puls code modulation is performed')
  for k=1:noRangeBins
    if (sammansattning == 1)
      Nt = getm(NNt,':',k,':',1,1);
      Nt = reshape(Nt,noElem,noPulses);
      X = A*B + Nt;
    elseif (sammansattning == 2)
      X = A*B;
    elseif (sammansattning == 3)
      Nt = getm(NNt,':',k,':',1,1);
      Nt = reshape(Nt,noElem,noPulses);
      X = Nt;
    else
      error('DBT-Error: Sammans鋞tningen finns inte.')
    end%if
    XX = setm(XX,X.', ':',k,':',1,1);  % Should be .' instead of ' ??? conj
    disploop(k, noRangeBins)
  end%for
else
  for k=1:L
    if (sammansattning == 1)
      Nt = getm(NNt,':',k,':',1,1);
      Nt = reshape(Nt,noElem,noPulses);
      X = pulsecode(k)*A*B + Nt;
    elseif (sammansattning == 2)
      X = pulsecode(k)*A*B;
    elseif (sammansattning == 3)
      Nt = getm(NNt,':',k,':',1,1);
      Nt = reshape(Nt,noElem,noPulses);
      X = Nt;
    else
      error('DBT-Error: Sammans鋞tningen finns inte.')
    end%if
    XX = setm(XX,X.', ':',k,':',1,1);  % Should be .' instead of ' ??? conj
    disploop(k, L)
  end%for
end
if noRangeBins>L
  for k=L+1:noRangeBins
    if (sammansattning == 1)
      Nt = getm(NNt,':',k,':',1,1);
      Nt = reshape(Nt,noElem,noPulses);
      X = Nt;
    elseif (sammansattning == 2)
      X = zeros(noElem,noPulses);
    elseif (sammansattning == 3)
      Nt = getm(NNt,':',k,':',1,1);
      Nt = reshape(Nt,noElem,noPulses);
      X = Nt;
    else
      error('DBT-Error: Sammans鋞tningen finns inte.')
    end%if
    XX = setm(XX,X.', ':',k,':',1,1);  % Should be .' instead of ' ??? conj
    disploop(k, noRangeBins)
  end%for
end
dbtinfo('');	%New line.


% ----------------------------------------------------------------------- %
% Return data.
% ----------------------------------------------------------------------- %
signals = zerosm([noPulses,noRangeBins,noElem,1,1]); % Only one trial is implemented.
for k=1:noRangeBins
  X  = getm(XX,':',k,':',1,1);
  signals = setm(signals, X, ':',k,':',1,1);
end

if (~(isstruct(waveform)))
  waveform = defwave(lambda,noRangeBins,noPulses,pulsecode,[]);
  %else
  %  waveform.wavelength = lambda;
end%if

new = 1;
if (new)
  sigvar = RxRadarSigT(signals, {antenna, waveform});
else
  sigvar.dataType = 'RxRadarSigT';
  sigvar.signals = signals;

  sigvar.antenna = antenna;
  sigvar.waveform = waveform;
end%if

%endfunction compsim5




function disploop(counter, maxNo)
    infoStr = sprintf('compsim5: ranbin = %d(%d)\r',counter,maxNo);
    dbtinfo(infoStr,1);
%endfunction disploop