1. A method comprising: determining by at least one processor a first parameter that indicates a first modulation and coding rate set for a first shared channel codeword and a second parameter that indicates a second modulation and coding rate set for a second shared channel codeword; determining by the at least one processor from a locally stored mapping rule a bit sequence that explicitly indicates the first parameter and that implicitly indicates the second parameter; and sending from a transmitter a first control channel codeword with the bit sequence that explicitly indicates the first parameter for the first shared channel codeword and sending from the transmitter a second control channel codeword companion to the first control channel codeword, wherein the second parameter for the second shared channel codeword is implicitly indicated by the bit sequence that is explicit in the first codeword.