The channel state information (CSI)at base station (BS),obtained from users in the multiuser multiple input multiple output (MU-MIMO)system,leads to precoding performance degradation in frequency division duplexing (FDD)system.Existing robust beamforming precoding algorithms in MU-MIMO can reduce the performance loss caused by imperfect CSI.However,these algorithms only take one or two robustness channel errors into consideration,as a conse-quence,the system performance is limited to be improved.By establishing joint channel error model including channel esti-mation error,quantization error and delay error,we derive the closed-form solution of robust beamforming matrix based on minimum mean square error (MMSE).And then,we derive the closed-form solution of robust beamforming matrix based on MMSE of signal leakage with distributed characteristics while applying to distributed communication system.When com-pared to the traditional MMSE algorithm which only considers quantization error,numerical analysis shows that,the proposed centralized and distributed downlink MU-MIMO beamforming algorithms have better sum rate and bit error rate (BER),and reduce the precoding performance loss caused by the above three channel errors.%在下行多用户多入多出（MU-MIMO）系统中，基站（BS）所获得的非理想信道状态信息（CSI）会导致频分双工（FDD）系统预编码性能变差。现有的MU-MIMO鲁棒预编码算法虽然可以对抗非理想CSI所导致的系统性能损失，但其只考虑其中一种或两种信道误差的鲁棒性，因此系统性能提升有限。本文通过建立包含信道估计误差、量化误差和延时误差的联合信道误差模型，推导出具有集中式特性的基于最小均方误差（MMSE）的鲁棒波束成形矩阵的闭式解；随后将这种信道条件应用到分布式通信系统，并推导出具有分布式特性的基于信号泄露的MMSE的鲁棒波束成形矩阵的闭式解。数值分析表明，本文所提的集中式和分布式MU-MIMO波束成形算法，与只考虑量化误差的鲁棒MMSE算法相比，具有更优的系统和速率与误码率，补偿了上述三种信道误差所导致的预编码性能损失。
展开▼
