A General Write Channel Model for Bit-Patterned Media Recording

In this paper, we propose a general write channel model for bit-patterned media recording by adding physically justifiable noise and feedback to the previously studied model. First, we study the noisy writing process by discussing several sources of errors causing some extra disturbances during the write process, in addition to data-dependent write synchronization errors that were studied before. Then, for this generalized model with various input and state distributions, we obtain information rate lower and upper bounds including the previous bounds as special cases. Second, a simplified feedback in the proposed channel is considered which stems from the special features of writing, and the behavior of this channel is analyzed in response to the feedback and compared mathematically and numerically with the situation, at which the feedback is ignored.