Function: phaselock
PHASELOCK  Phaselock Gabor coefficients
  Usage:  c=phaselock(c,a);

  PHASELOCK(c,a) phaselocks the Gabor coefficients c. The coefficients
  must have been obtained from a DGT with parameter a.

  Phaselocking the coefficients modifies them so as if they were obtained
  from a time-invariant Gabor system. A filter bank produces phase locked
  coefficients.

  Phaselocking of Gabor coefficients correspond to the following transform:
  Consider a signal f of length L and define N=L/a.
  The output from c=PHASELOCK(dgt(f,g,a,M),a) is given by

                 L-1 
    c(m+1,n+1) = sum f(l+1)*exp(-2*pi*i*m*(l-n*a)/M)*conj(g(l-a*n+1)), 
                 l=0  

  where m=0,...,M-1 and n=0,...,N-1 and l-an is computed modulo L.

  PHASELOCK(c,a,'lt',lt) does the same for a non-separable lattice
  specified by lt. Please see the help of MATRIX2LATTICETYPE for a
  precise description of the parameter lt.


  References:
    M. Puckette. Phase-locked vocoder. Applications of Signal Processing to
    Audio and Acoustics, 1995., IEEE ASSP Workshop on, pages 222 --225,
    1995.
    

Url: http://ltfat.github.io/doc/gabor/phaselock.html

See also: dgt, phaseunlock, symphase.

Package: ltfat