1. A method, comprising: transmitting data wirelessly using a hybrid automatic repeat request (HARQ) procedure in which one or more acknowledgement (ACK) messages or one or more negative-acknowledgement (NACK) messages, or both, are received by a transmitter from a receiver in accordance with the HARQ procedure with respect to the wireless data transmission; monitoring a number of ACK messages or a number of NACK messages received by the transmitter from the receiver during each of a plurality of durations of a given length; determining a modulation and coding scheme (MCS) level used in the wireless data transmission based on at least one of the number of ACK messages and the number of NACK messages received during a first duration of the plurality of durations; and adjusting the MCS level based on a comparison of: the number of ACK messages or the number of NACK messages received during a second duration of the plurality of durations, with: the number of ACK messages or the number of NACK messages received during the first duration of the plurality of durations.