Blind Signal Processing: Recent Results and Open Problems
    
            Andrzej Cichocki and Andrew Back
    
        Laboratory for Artificial Brain Systems, 
             Frontier Research Program RIKEN, 
      Institute of Physical and Chemical Research, 
                Hirosawa 2-1, Wako-shi,
                 Saitama 351-01, JAPAN
    
                        Abstract
    
In this brief overview, we present some basic or fundamental
problems associated with blind signal processing. We discuss 
briefly, the following problems: blind signal separation and 
blind extraction of signals from an instantaneous mixture, 
noise reduction and cancellation, blind separation of delayed 
source signals, and blind deconvolution/equalization of single 
and multichannel systems. Several promising approaches are 
discussed in the paper. Emphasis is given to neural network or
adaptive nonlinear filtering models and associated on-line 
adaptive learning algorithms.