Covering radii of even subcodes of t-dense codes
We introduce t-density for codes to find either the exact value of or an upper bound on the covering radius of even subcodes. We find results on the number of cosets of maximum weight of even subcodes. Exact results are obtained for, among others, the s-error-correcting BCH codes (s=1,2,3), punctured RM codes, and some QR codes. An algorithm for computing covering radius of t-deficient codes is used in one case. Some extensions are announced.
Preliminary versions of this paper were presented at the IEEE International Symposium on Information Theory, Brighton, June 24–28, 1985, and at AAECC, the 3rd International Conference on Applied Algebra, Algebraic Algorithms, and Error-correcting Codes, Grenoble, July 15–19, 1985.
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