A method of precoding implemented in a base station used in a wireless communications system having codebooks for multiple transmission ranks is disclosed. The method includes precoding data in one or more layers with a precoding matrix obtained from one of the codebooks, and transmitting the precoded data to a user equipment, wherein entries of said one of the codebooks are accessed through a first description and a second description, wherein the precoding matrix is determined according to the first description and the second description, which are unique to the precoding matrix, and wherein the second description provides a finer description of said one of the codebooks than the first description. Other methods, systems, and apparatuses also are disclosed.