Abstract: A system and method for mapping and decoding codewords in acknowledgement information communications are provided. A method for communications device operations includes determining a hybrid automatic repeat request (HARQ) response for each component carrier (CC) in a set of configured CCs, thereby producing a set of HARQ responses, generating an information vector from the set of HARQ responses, encoding the information vector based on a (n, k) linear block code corresponding to the set of configured CCs, and transmitting the encoded information vector. A unique set of bits selected from the information vector is assigned to represent a HARQ response for each different CC in the set of configured CCs. The (n, k) linear block code is obtained by a linear transformation of an original (n, k) linear block code, where n is a length of code words, and k is a length of information vectors.