The present invention discloses constructs and methods for transmitting a HARQ re-transmission in an adaptive manner in a wireless communication system. The system of the present invention discloses: scheduling the re-transmission of a data packet, based on decoding results from a receiver; determining a plurality of parameters for re-transmission in an adaptive manner; sending an assignment message if required; using a plurality of fields in the assignment message for re-transmission to indicate the plurality of parameters in the re-transmission; using a MACID field in the assignment message for re-transmission to indicate a target mobile station for the re-transmission; transmitting a data packet for the re-transmission; and decoding the data packet at the receiver to determine if a further need of re-transmission exists.