Lemma for Linear Feedback Shift Registers and DFTs Applied to Affine Variety Codes
Lemma for Linear Feedback Shift Registers and DFTs Applied to Affine Variety Codes
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DOI:
10.1109/tit.2014.2311042
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发表时间:
2012-11
影响因子:
2.5
通讯作者:
H. Matsui
中科院分区:
文献类型:
--
作者:
H. Matsui
In this paper, we establish a lemma in algebraic coding theory that frequently appears in the encoding and decoding of, e.g., Reed-Solomon codes, algebraic geometry codes, and affine variety codes. Our lemma corresponds to the nonsystematic encoding of affine variety codes, and can be stated by giving a canonical linear map as the composition of an extension through linear feedback shift registers from a Gröbner basis and a generalized inverse discrete Fourier transform. We clarify that our lemma yields the error-value estimation in the fast erasure-and-error decoding of a class of dual affine variety codes. Moreover, we show that systematic encoding corresponds to a special case of erasure-only decoding. The lemma enables us to reduce the computational complexity of error-evaluation from O(n3) using Gaussian elimination to O(qn2) with some mild conditions on n and q, where n is the code length and q is the finite-field size.