BEHAVIOUR OF FSSMS OVER GF(4) AS CONSTITUENT ENCODERS OF A TURBO CODE

PETRUZZI, D. M.; LIBERAORI, M. C.; BONADERO, J. C.; CASTIÑEIRA MOREIRA, J.

Mar del Plata, Argentina

Congreso; Congreso AST 36 JAIIO; 2007

In this paper we analyse the performance of Finite State Sequence Machines (FSSMs) designed over the Galois Field GF(4). These FSSMs have the property of showing a non-zero output for the all-zero input case. A relationship is found between the state transitions structure, the randomness of the corresponding output of the responses to the all-zero input for different initial state conditions, the BER performance and the form of the corresponding EXIT chart. It is found that FSSMs with responses of the form of long closed cycles, and good randomness properties of the corresponding output, are the best options as constituent encoders of non-linear turbo codes designed over GF(4).