Generalization of Steane's Enlargement Construction of Quantum Codes and Applications

We generalize Steane's enlargement construction of binary quantum codes to
q
-ary quantum codes. We then apply this result to BCH codes and the study of asymptotic bounds, and obtain improvements to the quantum BCH codes constructed by Aly and Klappenecker and the quantum asymptotic bounds from algebraic geometry codes obtained by Feng, Ling, and Xing.