Latin American applied research
versión ISSN 0327-0793
CASTINEIRA MOREIRA, J.; PETRUZZI, D.M.; LIBERATORI, M.C. y BONADERO, J. C.. Non-punctured non-systematic ½-rate turbo codes. Lat. Am. appl. res. [online]. 2009, vol.39, n.3, pp. 201-206. ISSN 0327-0793.
This paper presents non-punctured non-systematic ½-rate turbo codes designed using Finite State Sequential Machines (FSSMs) that operate over the Finite Field GF(4). It is shown that these schemes do not show convergence problems in their iterative decoding, as it happens to similar schemes defined over the binary Field. Non-systematic turbo codes can be useful for the design of communication systems for which error correction and encryption are two important goals. A relationship is found between the state transitions structure of the FSSM and the BER performance (or equivalently the form of the EXIT chart) of the designed turbo code. FSSMs defined over GF(4) with all-zero input responses of the form of closed cycles are the best options as constituent encoders of non-punctured non-systematic ½-rate turbo codes. A close relationship is also found between the BER performance and the coefficients that define the structure of those FSSMs.
Palabras llave : Turbo Codes; EXIT Charts; Non-Systematic Coding; Non-Linear Coding.