Enhanced line search applied to blind channel identification identifiability conditions

Abstract

The ALS algorithm, used to fit the PARAFAC model, sometimes needs a large number of iterations before converging. The slowness in convergence can be due to the large size of the data, or to the presence of degeneracies, etc. Several methods have been proposed to speed up the algorithm, some of which are compression (R. Bro and C.A. Andersson, 1998), and line search (R. Bro, 1998). In M. Rajih and P. Comon (2005) presents a novel method for speeding up the algorithm, enhanced line search (ELS), that shows better results in simulations compared to the existing methods, especially in the case of degeneracy. This paper gives an application of ELS to blindly identify the mixing matrix of an under-determined mixture (UDM): algorithm ALESCAF, and states the identifiability conditions based on ALESCAF