Full paper in PDF:
$%A. Fúster Sabater and L. J. García Villalba, Sobre el parámetro complejidad lineal y los filtros no
lineales de segundo orden, Rev. Mat. Complut. 13 (2000), no. 1, 119–134.%$
Sobre el parámetro complejidad lineal y los
filtros no lineales de segundo orden
Amparo FÚSTER SABATER and Luis J. GARCÍA VILLALBA
Departamento de Tratamiento de la Información y Codificación
Instituto de Física Aplicada (CSIC)
Serrano 114
28006 Madrid — Spain
Received: January 18, 1999
Revised: July 1, 1999
A new method of analyzing the linear complexity of 2nd order nonlinear filterings
of
-sequences that is based on the concept of regular coset is presented. The
procedure considers any value of the LFSR’s length,
(prime or composite
number). Emphasis is on the geometric interpretation of the regular cosets which
produce degeneracies in the linear complexity of the filtered sequence. Numerical
expressions to compute the linear complexity of such sequences are given as well
as practical rules to design 2nd order nonlinear filterings which preserve the
maximal linear complexity are stated.
1991 Mathematics Subject Classification: 11K45, 94A55.