Patent attributes
The present invention realizes a decoder and an error position polynomial calculation method which realize erasure corrections by making less changes to a conventional Berlekamp algorithm calculation circuit. An error position polynomial σ(x) is calculated on the basis of a syndrome S0, S1, . . . , S2t−1 and erasure position data Er0, Er1, . . . , Er2t−1 as Galois field expressions of erasure positions. In addition, switching of connection between buffers holding uncompleted operation results and an operator is controlled based on the number of erased received symbols and the number of processing steps, so that derivations of both the erasure position polynomial and the error position polynomial from erasure position data can be realized by the same circuit (an error position polynomial calculator).
