Closed-form power allocation scheme for space-time coded multiple-antenna systems with imperfect CSI

This paper presents a closed-form power allocation scheme for space-time coded multiple-antenna systems with imperfect channel state information at the transmitter. The proposed scheme is based on a so-called compressed signal-to-noise ratio (CSNR) criterion, where a single compression factor is used to minimize the bit-error-rate (BER). The obtained closed-form solution is computational efficient and achieves almost the same performance as the existing optimal approach which requires numerical search, and outperforms the existing suboptimal closed-form algorithm.