5. A decoding apparatus according to claim 3; wherein said error position detector has a memory for storing therein error position data for one block comprising a plurality of words.
5. A decoding apparatus according to claim 3; wherein said error position detector has a memory for storing therein error position data for one block comprising a plurality of words. 7. A decoding means according to claim 5; wherein said estimator estimates a bit position in which the probability of an error is highest in one word as an error position according to error position data for said first word and said second word stored in said memory.