— A hybrid automatic repeat-request (ARQ) code combining scheme employing different multidimensional spacetime trellis codes (MSTTCs) over a multiple-input, multipleoutput (MIMO) channel is described. The retransmission codes are designed using sub-optimal partition chains of the MSTTC super-constellation using a relatively simple search. The MSTTCs designed using the sub-optimal partition chain are, by themselves, not optimal codes. But when combined with the coded packet used for previous transmission(s), they provide better error control than using the same code for all transmissions. Theoretical performance analysis and simulation results are provided.