Space-time block coding with channel state information for transmit diversity

In this paper, a transmit diversity technique, space-time block coding (STBC) with channel state information (CSI) at the transmitter, is presented for the downlink of a wireless communication system, which consists of a user terminal with double antennas and a base station with multiple antennas, where the STBC without CSI proposed by Alamouti is applied to the uplink. The user terminal of such a system may require no CSI for both coding and decoding so that its complexity can be considerably reduced when MPSK modulations are employed. Compared with the maximum ratio transmission (MRT) scheme, the STBC with CSI suffers from only 2 dB performance degradation.