Advanced decoding algorithms for Reed-Solomon/Convolutional concatenated codes

The evaluation of the union bound for the BER of Reed-Solomon/Convolutional concatenated codes indicates that their performance might largely improve through the application of soft iterative decoders. This paper presents an iterative decoding algorithm for concatenated codes consisting of an outer Reed-Solomon code, a symbol interleaver and an inner convolutional code. The performance improvement for iterative and non-iterative decoders is evaluated. Existing solutions for the different decoding stages and their interfaces are discussed and their performance is compared. A new procedure is proposed to define the feedback signal from the output of the Reed-Solomon decoder to the input of the convolutional decoder, which captures the reliability information that can be inferred from errors-and-erasures RS decoders and includes the "state pinning" approach as a particular case. The decoding schemes are applied to the specific DVB-S concatenated code.