Abstract: A decoder device includes: a decoder that decodes data stored in a storage medium by performing error correction on the data, the error correction being capable of correcting code error and code erasure included in the data; a memory that stores a history of an address in the storage medium of a code included in the data, the code being detected to have the code error by the decoding unit; and a controller that controls the decoder to change a detail of the error correction based on the history stored in the memory.

Abstract: A wireless communication system includes a first communication apparatus, a second communication apparatus, and a third communication apparatus which are mutually communicable by wireless. The second communication apparatus includes a receiving section for receiving a signal and a transmission section. The transmission section transmits a first transmission signal whose destination is the third communication apparatus with power enough to reach both the first communication apparatus and the third communication apparatus, and transmits a second transmission signal whose destination is the third communication apparatus in accordance with a response signal from the third communication apparatus including an information related to received power or receipt quality of the first transmission signal in the third communication apparatus with power enough to reach the third communication apparatus.