Enhanced line search for blind channel identification based on the Parafac decomposition of cumulant tensors

In this paper we consider higher-order cumulant based methods for the blind estimation of a single-input single-output finite impulse response system driven by a non- Gaussian signal. This problem can be interpreted as a particular polynomial optimization problem. Using the link between this problem and the parallel factor decomposition of a third-order tensor we present a new representation of the cost function and give an explicit expression for its complex gradient. Then we explore convergence/non convergence of the single-step least- squares algorithm and improve it by enhanced line/plane search procedures.