A Link between Guruswami--Sudan's List--Decoding and Decoding of Interleaved Reed--Solomon Codes

The Welch--Berlekamp approach for Reed--Solomon (RS) codes forms a bridge between classical syndrome--based decoding algorithms and interpolation--based list--decoding procedures for list size l=1. It returns the univariate error--locator polynomial and the evaluation polynomial of the RS code as a y-root. In this paper, we show the connection between the Welch--Berlekamp approach for a specific Interleaved Reed--Solomon code scheme and the Guruswami--Sudan principle. It turns out that the decoding of Interleaved RS codes can be formulated as a modified Guruswami--Sudan problem with a specific multiplicity assignment. We show that our new approach results in the same solution space as the Welch--Berlekamp scheme. Furthermore, we prove some important properties.