Z4‐Kerdock Codes, Orthogonal Spreads, and Extremal Euclidean Line‐Sets
Z4‐Kerdock Codes, Orthogonal Spreads, and Extremal Euclidean Line‐Sets
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DOI:
10.1112/s0024611597000403
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发表时间:
1997-09
影响因子:
1.8
通讯作者:
A. Calderbank;P. Cameron;W. Kantor;JJ Seidel
中科院分区:
文献类型:
--
作者:
A. Calderbank;P. Cameron;W. Kantor;JJ Seidel
When m is odd, spreads in an orthogonal vector space of type Ω+(2m + 2,2) are related to binary Kerdock codes and extremal line‐sets in 2m + 1 with prescribed angles. Spreads in a 2m‐dimensional binary symplectic vector space are related to Kerdock codes over Z4 and extremal line‐sets in \CC2m with prescribed angles. These connections involve binary, real and complex geometry associated with extraspecial 2‐groups. A geometric map from symplectic to orthogonal spreads is shown to induce the Gray map from a corresponding Z4‐Kerdock code to its binary image. These geometric considerations lead to the construction, for any odd composite m, of large numbers of Z4‐Kerdock codes. They also produce new Z4‐linear Kerdock and Preparata codes. 1991 Mathematics Subject Classification: primary 94B60; secondary 51M15, 20C99.