Methods and apparatuses for implementing error-correction in communication systems, particularly wireless communication systems. Input bits are encoded according to a chained generator matrix to generate a codeword, and the codeword is transmitted. The chained generator matrix includes a first subset of entries corresponding to a first subset of entries in a base generator matrix for a chained polar code, and a second subset of entries that are different from a second subset of entries in the base generator matrix. A chained generator matrix could be constructed, for example, by applying a chaining matrix to the second subset of entries in the base generator matrix, to produce the second subset of entries in the chained generator matrix.