Quasi-perfect codes with small distance
The main purpose of this paper is to give bounds on the length of the shortest and longest binary quasi-perfect codes with a given Hamming distance, covering radius, and redundancy. We consider codes with Hamming distance 4 and. 5 and covering radius 2 and 3, respectively. We discuss the blockwise direct sum (BDS) construction which has an important role in finding these bounds.
quasi-perfect codes covering blockwise direct sum (bds) construction density packing