In this paper we analyze the performance in terms of Bit Error Rate (HER) and Frame Error Rate (FER) of a duo-binary turbo coded system over Rayleigh flat fading channels. The turbo codes (TCs) proposed here are constructed from parallel concatenation of two identical rate 2/3 recursive systematic convolutional RSC codes. It results rate 1/2 Duo-Binary Turbo Codes (DBTCs). Data block length has k=mxN=2x752 bits. We consider the family of interleaver proposed in 2005 by C. Douillard and C. Berrou which is simpler to implement in hardware. The results from this paper show that the two DBTC found by us, outperforms the DBTC proposed in literature with more than 0.2 dB for a BER<10(-6) and a FER of 10(-4), also when a Rayleigh channel is considered.