New Codes via the Lengthening of BCH Codes with UEP Codes

We describe a code lengthening technique that uses unequal error protection codes as suffix codes and combine it with iteration of the conventional Construction X. By applying this technique to BCH codes, we obtain five new binary codes, 13 new ternary codes, and 13 new quarternary codes. An improvement of Construction XX yields two new ternary codes.