Nine good rate (m-1)/pm quasi-cyclic codes
Thomas Aaron Gulliver, V.K. Bhargava · IEEE Transactions on Information Theory · 1992
The class of quasi-cyclic (QC) codes has been proven to contain many good codes. To date the known results are largely codes of the form 1/p and (p-1)/p constructed from circulant matrices. A generalization of these rate 1/p codes to rate (m-1)/pm codes based on the theory of 1-generator QC codes is presented. The results of a search for good codes based on heuristic combinatorial optimization are nine codes which improve the known lower bounds on the minimum distance of binary linear codes.>