Joint subspace beamforming and space-time coding in wireless MIMO systems

In this paper, we propose a new joint beamforming and space-time coding (STC) scheme for wireless multiple-input multiple-output (MIMO) systems based on block singular value decomposition (BSVD). By utilizing the BSVD, transmit and receive beamformers divide the MIMO channel into some decoupled MIMO subchannels, which have different sizes. Due to flexibility in dividing the MIMO channel and applying the STC to each MIMO subchannel independently, the system can be designed based on trade off between diversity, multiplexing and complexity. Combining the dominant subspace beamformer and Alamouti STC, which is developed based on one dimensional BSVD (1D-BSVD), can be considered as one approach. To evaluate the performance of the new approach, the bit error rate (BER) of the proposed joint beamforming and ST coding is compared with the BERs of the orthogonal space-time block codes (OSTBCs) and the quasi-OSTBCs (QOSTBCs) via computer simulations. The results show that the superior performance of the proposed approach.