32 states double binary turbo code

As a result of exhaustive searches on the set of memory 5 systematic and recursive component encoders, the paper proposes a double binary turbo code (DBTC) incorporating the best encoder found. The proposed DBTC´s performances in terms of bit error rate (BER) and frame error rate (FER) show a substantial reduction in the error floor effect and superior convergence to the memory 4 DBTC in DVB-RCS2 standard. In the paper are presented: the family of double-binary convolutional encoders of memory 5, the selection algorithm used to identify the most efficient encoder, the performance obtained by incorporating the selected encoder in the turbo-code. The proposed turbo code works at a distance of about 0.6 dB from the theoretical limit, even for FER values below 10^-9. The use of such a turbo code is recommended in applications where a very small error rate is desired.