Prior to turbo codes, the best constructions were serial [[concatenated code]]s based on an outer [[Reed-Solomon error correction]] code combined with an inner [[Viterbi algorithm|Viterbi-decoded]] short constraint length [[convolutional code]], also known as RSV codes.
In a later paper, Berrou generously gave credit to the intuition of "G. Battail, [[Joachim Hagenauer|J. Hagenauer]] and P. Hoeher, who, in the late 80s, highlighted the interest of probabilistic processing." He adds "[[Robert G. Gallager|R. Gallager]] and M. Tanner had already imagined coding and decoding techniques whose general principles are closely related," although the necessary calculations were impractical at that time.<ref>{{Citation|first=Claude|last=Berrou|title=The ten-year-old turbo codes are entering into service|___location=Bretagne, France|accessdate=11 February 2010|url=https://www.researchgate.net/publication/3199004_The_ten-year-old_turbo_codes_are_entering_into_service}}</ref>
