Combining beamforming with Alamouti scheme for multiuser MIMO communications

We combine optimum receive beamforming with the Alamouti space-time block code (STBC) transmission and modify the decoding process. In a multiuser multiple-input multiple-output (MIMO) communications scenario, the beamformer suppresses cochannel interference (CCI) by maximizing the uplink signal-to-noise-plus-interference ratio (SINR). It is shown that the beamforming process increases the bit-error-rate (BER) performance and maximizes the available uplink channel capacity for each user in the presence of CCI. The ergodic capacity of a conventional 2-by-1 Alamouti scheme is also increased from 3.2 to 4 bits/s/Hz by adding one receive antenna.