Micro-local analysis in some spaces of ultradistributions
  In this paper we extend some results from our earlier papers on wave-front sets, concerning wave-front sets of Fourier-Lebesgue and modulation space types, to a broader class of spaces of ultradistributions, and relate these wave-front sets with the usual wave-front sets of ultradistributions.   Furthermore, we use Gabor frames for the description of discrete wave-front sets, and prove that these wave-front sets coincide with corresponding continuous ones. 
Karoline Johansson, Stevan Pilipovic, Nenad Teofanov, Joachim Toft
math.FA