A channel with memory has the characteristics of introducing correlated error bursts in transmitted data symbols. The inter-symbol interference and dropout effects in magnetic tape channels contribute to correlated error sequences in the read-back signal. A product-code-based error correcting scheme is used in conventional tape drive systems to combat these effects and to guarantee very high data fidelity. The read-back signal from the tape is decoded using a hard-decision distance-bounded decoder of the product code. In this paper, we present an analytical method to evaluate the performance of product codes on tape channels described as hidden Markov models. The performance measures of interest are symbol and codeword error rates of product codes. In addition to presenting the performance curves of the product code used in present day tape drive systems, we propose alternate error correcting schemes that can be considered for implementation in future generations.
By: S. Sankaranarayanan; Evangelos S. Eleftheriou
Published in: Proc. IEEE Int'l Symp. on Information Theory "ISIT 2005," Adelaide, Australia, September 2005 (IEEE, 2005).Adelaide, Australia in 2005
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