1. A method for minimizing errors in communicating packets comprising symbols, for use in a multiple-input-multiple-output (MIMO) space-time coded (STC) packet radio communications system having at least two transmit antennas, the method comprising: a) determining a sequence of transmitter STC code mappings, the sequence including at least two STC code mappings; b) transmitting a packet using a first STC code mapping in the sequence; c) detecting a first transmission error and retransmitting the packet using a subsequent STC code mapping in the sequence; d) detecting a subsequent transmission error and, if there are further STC code mappings, retransmitting the packet using a further subsequent STC code mapping in the sequence, else retransmitting the packet using the first STC code mapping in the sequence; e) repeating the step d) as necessary.