A method and a device (20) for decoding a frame capable of being split into p sub-frames each consisting of k information symbols, a first n−k redundant symbols and a last n−k redundant symbols. The decoding process uses two individual decoders (21, 23) which concurrently produce extrinsic data (Extr1i, Extr2i) respectively concerning information symbols and interleaved information symbols. The values of the extrinsic data (Extr1i, Extr2i) are refined by cross-feedback of said data to the input of the decoders (21, 23).