ARQ protocols for MIMO systems

In this paper, we evaluate the performance of Automatic Repeat reQuest (ARQ) protocols for MIMO (Multiple In Multiple Out) Systems using fixed and adaptive Modulation based on the instantaneous Signal to Noise Ratio (SNR). Transmit Antenna Selection (TAS) or/and Space Time Block Coding (STBC) are used. At the receiver, Maximum Ration Combining (MRC), Selection Combining (SC), Generalized SC (GSC), Minimum Selection GSC (MSGSC) and Maximum Likeliood (ML) detection are used. We also propose a combination of TAS and STBC where STBC is performed over two selected best antennas. We provide an analysis of the throughput performance of ARQ for MIMO systems using different transmitting and receiving techniques. Simulation results are also provided to confirm the accuracy of the theoretical analysis.