Title
Subspace polynomials and limits to list decoding of Reed-Solomon codes
Abstract
We show combinatorial limitations on efficient list decoding of Reed-Solomon codes beyond the Johnson-Guruswami-Sudan bounds. In particular,we showthat for arbitrarily large fields FN, |FN| = N, for any δ Ɛ, (0,1) and K = Nδ : • Existence: there exists a received word wN : FN → FN that agrees with a super-polynomial number of distinct degree K polynomials on ≈ N√δ points each; • Explicit: there exists a polynomial time constructible received word w1N : FN → FN that agrees with a superpolynomial number of distinct degree K polynomials, on ≈ 2√logN K points each. In both cases, our results improve upon the previous state of the art, which was ≈ Nδ/δ points of agreement for the existence case (proved by Justesen and Hoholdt), and ≈ 2Nδ points of agreement for the explicit case (proved by Guruswami and Rudra). Furthermore, for δ close to 1 our bound approaches the Guruswami-Sudan bound (which is √NK) and implies limitations on extending their efficient Reed-Solomon list decoding algorithm to larger decoding radius. Our proof is based on some remarkable properties of subspace polynomials. Using similar ideas, we then present a family of low rate codes that are efficiently list-decodable beyond the Johnson bound. This leads to an optimal list-decoding algorithm for the family of matrixcodes.
Year
DOI
Venue
2010
10.1109/TIT.2009.2034780
IEEE Transactions on Information Theory
Keywords
Field
DocType
larger decoding radius,logn k,existence case,subspace polynomial,reed-solomon code,bound approach,efficient reed-solomon list,distinct degree k polynomial,k polynomial,distinct degree,efficient list,reed solomon,polynomials,reed solomon code,polynomial time,list decoding,artificial intelligence,decoding
Discrete mathematics,Binary logarithm,Combinatorics,Subspace topology,Polynomial,Reed–Solomon error correction,Johnson bound,Decoding methods,List decoding,Time complexity,Mathematics
Journal
Volume
Issue
ISSN
56
1
0018-9448
Citations 
PageRank 
References 
11
1.19
14
Authors
3
Name
Order
Citations
PageRank
Eli Ben-Sasson1164186.98
Swastik Kopparty238432.89
Jaikumar Radhakrishnan3112396.04