Adaptive space-time coding system in fading channels

Recently, there has been increasing interest in providing high quality and efficient broadband services over wireless and mobile links. One powerful performance enhancing technique, which holds the promise of offering a significant increase in the system information capacity, is the adaptive antenna array. Space-time codes (STC) are designed to exploit multi-input and multi-output (MIMO) antenna systems and by doing so an enormous increase in the capacity of wireless systems can be achieved. In this paper, an adaptive space-time coding (ASTC) technique, which combines STC together with singular value decomposition (SVD), is designed to improve the performance of STC when the channel state information (CSI) is available at the transmitter. To demonstrate the potential of the proposed scheme, simulation results are presented and are compared with conventional STC. In particular, the proposed system sensitivity to channel estimation errors at the transmitter is thoroughly investigated.