function [rec,lse] = rec_complex (theta,NF,N)% ===================================================================% function [rec,lse] = rec_complex (theta,NF,N)% -------------------------------------------------------------------% Reconstructs a sequence based on knowledge of its phase within a% linear phase component. The length of the sequence is unknown.%% theta   :  the phase sequence% NF      :  the FFT size% N       :  an estimate of the length of the reconstructed sequence%% rec     :  the reconstructed sequence% lse     :  least-squares-error%% Author: H. Pozidis,   September 23, 1998% ===================================================================lse=[];  NI=N;  W=-1;   % Range within which to search from the length N.vv=[NI-W:NI+W]; vv=4*vv-3;  vv=sum(vv);REC=zeros(vv,NI+abs(W));nloop=1;for N=NI-W:NI+W  for shift=0:0.5:0.5    psi1=theta+(2*pi/NF)*[0:NF-1]*shift;    psi1=psi1(:);    for a=0:N-1      vec1=[-(N-1-a):a];         pies1=(2*pi/NF)*[0:NF-1]'*vec1;      for j=1:length(vec1)        ang1(1:NF,j)=psi1;       end      Phi1=sin(pies1+ang1);      Phi2=-cos(pies1+ang1);        PHI=[Phi1 Phi2];      [U,S,V]=svd(PHI);       [si,sj]=sort(diag(S));      UU=V(:,sj);      u=UU(:,1);      rec=u(1:N)+sqrt(-1)*u(N+1:2*N);      rec=rec(:).';      err=(norm(PHI*u)^2)/NF;      lse=[lse err];      REC(nloop,:)=[rec zeros(1,NI+W-length(rec))];      nloop=nloop+1;    end  endend[lsm,lsi]=min(lse); rec=REC(lsi,:);f=find(rec ~= 0); rec=rec(f); %disp(size(rec));