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On the design of spectrum shaping codes for high-density data storage

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Abstract

This paper proposes systematic code design methods for constructing efficient spectrum shaping codes with the maximum runlength limited constraint k, which are widely used in data storage systems for digital consumer electronics products. Through shaping the spectrum of the input user data sequence, the codes can effectively circumvent the interaction between the data signal and servo signal in high-density data storage systems. In particular, we first propose novel methods to design high-rate k constrained codes in the non-return-to-zero (NRZ) format, which can not only facilitate timing recovery of the storage system, but also avoid error propagation during decoding and reduce the system complexity. We further propose to combine the Guided Scrambling (GS) technique with the k constrained code design methods to construct highly efficient spectrum shaping k constrained codes. Simulation results demonstrate that the designed codes can achieve significant spectrum shaping effect with only around 1% code rate loss and reasonable computational complexity.

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... Over the years, different construction schemes for RLL codes, with varied enhancements, have been proposed and analyzed [15]- [18]. Study of RLL codes has continued to be an important research topic, and recent work includes its application to high density data storage [19], DNA-based storage [20], and visible light communication [21]. ...
... Note from Prop. 10 that feasible subblock length L → ∞ as E max → ∞. Hence, using (19) and (1), ...
... The upper bound is computed using the expression h (max{B, 0.5}) which corresponds to the code capacity when the fraction of ones in each codeword is at least B (see Prop. 8 and the following remark). The lower bound for O Emax SEC (B) is computed using (19) and (1). As shown in Thm. ...
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... Note from Prop. 10 that feasible subblock length L → ∞ as E max → ∞. Hence, using (19) and (1), ...
... The upper bound is computed using the expression h (max{B, 0.5}) which corresponds to the code capacity when the fraction of ones in each codeword is at least B (see Prop. 8 and the following remark). The lower bound for O Emax SEC (B) is computed using (19) and (1). As shown in Thm. ...
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