Low complexity multi-user multi-stream vector perturbation with quantized channel feedback

In this paper, we propose a new minimum-total-mean-square-error criterion based robust vector perturbation (MTMSE-MUMS-VP) precoding algorithm for multiuser MIMO downlink with quantized channel feedback. The proposed new algorithm has much lower computational complexity and slightly better BER performance than traditional MTMSE-MUMS-VP algorithm. The quantitative relationship between the variance of vector quantization (VQ) and feedback load number is also derived for multi-user multi-stream systems. Simulation results show that 1) VP precoding algorithms need more accurate CSI than linear precoding; 2) In the scenario of 8 transmit antennas BS and 4 user with 2 receive antennas each, the error floor has been improved by 13% under feedback load B = 128 bits.