Interference aware MMSE equalization for MIMO TxAA

Closed loop transmission diversity will be an important part of the enhancements of todays wireless technologies, e.g. in double-stream transmit antenna array (D-TxAA). Despite the promise of performance gains, closed loop beamforming will introduce an interference scenario in the downlink that cannot easily be handled by the conventional MMSE equalization approach. In this paper, we derive an interference aware MMSE equalizer that uses the information about the beamforming vectors. The proposed equalizer can be calculated by utilizing a virtual channel description incorporating the beamforming weights. To assess the performance, we performed fading simulations with a system level description of the transmission. The derived equalizer shows only a small increase in complexity compared to the conventional approach, but perfectly restores the orthogonality.