Sobre dinamica caotica e convergencia em algoritmos de equalização autodidata

AUTOR(ES)
DATA DE PUBLICAÇÃO

2001

RESUMO

The objective of this work is to perform a dynamical analysis of the constant modulus algorithm (CMA) iterative expression. The analysis shows that the CMA, in both deterministic and stochastic versions, can present, besides the usual “convergence to fixed point” and “divergence” types of behavior, a very rich dynamical scenario, which includes period-doubling and chaos. These features are verified in detail for many linear channel/equalizer configurations, what provides a satisfactory scope for the conclusions in terms of the system model. A theoretical analysis, founded on the classical nonlinear dynamical systems theory and on more recent ideas, like markovian jumps, is carried out in order to establish a solid support to the discussion concerning the obtained results. Finally, we propose a method, based on some conclusions taken from the study, that may improve Bussgang algorithms global convergence in some situations. The applicability of the method is investigated for the CMA and also for the decision-directed (DD) algorithm, through simulations concerning different channel models.

ASSUNTO(S)

comportamento caotico nos sistemas processamento de sinais filtros adaptativos

ACESSO AO ARTIGO

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