Maximum Intersection of Linear Codes and Codes Equivalent to Linear

摘要

We consider linear codes in a space over a finite field with the Hamming metric. A code is called pseudolinear if it is the image of a linear code under an isometric transformation of the space. We derive an upper bound (q - 2)M/q attainable for q ? 3 for the size of the intersection of two different pseudolinear codes of the same size M.