A Practical Adaptive Transmission Scheme for Spatial Multiplexing MIMO Systems

We propose in this paper a practical adaptive modulation and channel encoding scheme for spatial multiplexing multiple-input multiple-output (MIMO) systems. The proposed scheme aims not only to maximize the average spectral efficiency (ASE) for a given bit error rate (BER) constraint but also to lower the computational and hardware complexity. First, an adaptive transmission principle for spatial multiplexing MIMO systems is presented under the assumption that the channel state information (CSI) is available at the receiver; Furthermore, we propose not only an adaptive modulation scheme for different transmit antennas but also an adaptive scheme which combines channel encoding and modulation. Finally we demonstrate from the simulation that the proposed scheme is of practical significance since it provides a well-behaved tradeoff between the ASE and complexity in comparison with the singular value decomposition (SVD) based adaptive transmission scheme with the optimal ASE performance and high computational complexity.