Capacity and coding for memories with real-time noisy defect information at both sides

The paper investigates the problem of information storage in defective media where a real-time noisy information about the defects is available at both the encoder and the decoder. The problem is modeled as communication over a finite state channel in the case where noisy state information is available at both sides. It is shown that this problem can be transformed into Shannon´s problem of a channel with side information (1958). An optimal coding strategy is described and the capacity is derived. In general the capacity is given in terms of strategies, and it is further shown that in some cases of interest the capacity can be described without employing Shannon strategies