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On Inverses for Quadratic Permutation Polynomials over Integer Rings (1102.2223v1)
Published 10 Feb 2011 in cs.IT and math.IT
Abstract: Quadratic permutation polynomial interleavers over integer rings have recently received attention in practical turbo coding systems from deep space applications to mobile communications. In this correspondence, a necessary and sufficient condition that determines the least degree inverse of a quadratic permutation polynomial is proven. Moreover, an algorithm is provided to explicitly compute the inverse polynomials.