Lattice-reduction-aided MMSE precoding for correlated MIMO channels and performance analysis  

作　　者：Rui Chen Jiandong Li Changle Li Wei Liu 

机构地区：[1]State Key Laboratory of Integrated Service Networks, Xidian University, Xi＇an 710071, P. R. China

出　　处：《Journal of Systems Engineering and Electronics》2012年第1期16-23,共8页系统工程与电子技术（英文版）

基　　金：supported by the National Science Fund for Distinguished Young Scholars (60725105);the National Basic Research Program of China (2009CB320404);the Program for Changjiang Scholars and Innovative Research Team in University (IRT0852);the 111 Project(B08038);the National Natural Science Foundation of China (60702057);the Special Research Fund of State Key Laboratory (ISN1102003);the National Science and Technology Major Project (2011ZX03001-007-01)

摘　　要：The lattice-reduction （LR） has been developed to im- prove the performance of the zero-forcing （ZF） precoder in multiple input multiple output （MIMO） systems. Under the assumptions of uncorrelated flat fading channel model and perfect channel state information at the transmitter （CSIT）, an LR-aided ZF precoder is able to collect the full transmit diversity. With the complex Lenstra- Lenstra-Lov^sz （LLL） algorithm and limited feedforward structure, an LR-aided linear minimum-mean-square-error （LMMSE） pre- coder for spatial correlated MIMO channels and imperfect CSIT is proposed to achieve lower bit error rate （BER）. Assuming a time division duplexing （TDD） MIMO system, correlated block flat fad- ing channel and LMMSE uplink channel estimator, it is proved that the proposed LR-aided LMMSE precoder can also obtain the full transmit diversity through an analytical approach. Furthermore, the simulation results show that with the quadrature phase shift keying （QPSK） modulation at the transmitter, the uncoded and coded BERs of the LR-aided LMMSE precoder are lower than that of the traditional LMMSE precoder respectively when Eb-No is greater than 10 dB and 12 dB at all correlation coefficients.The lattice-reduction （LR） has been developed to im- prove the performance of the zero-forcing （ZF） precoder in multiple input multiple output （MIMO） systems. Under the assumptions of uncorrelated flat fading channel model and perfect channel state information at the transmitter （CSIT）, an LR-aided ZF precoder is able to collect the full transmit diversity. With the complex Lenstra- Lenstra-Lov^sz （LLL） algorithm and limited feedforward structure, an LR-aided linear minimum-mean-square-error （LMMSE） pre- coder for spatial correlated MIMO channels and imperfect CSIT is proposed to achieve lower bit error rate （BER）. Assuming a time division duplexing （TDD） MIMO system, correlated block flat fad- ing channel and LMMSE uplink channel estimator, it is proved that the proposed LR-aided LMMSE precoder can also obtain the full transmit diversity through an analytical approach. Furthermore, the simulation results show that with the quadrature phase shift keying （QPSK） modulation at the transmitter, the uncoded and coded BERs of the LR-aided LMMSE precoder are lower than that of the traditional LMMSE precoder respectively when Eb-No is greater than 10 dB and 12 dB at all correlation coefficients.

关 键 词：multiple input multiple output （MIMO） lattice reduction correlated channel linear precoding. 

分 类 号：TN92[电子电信—通信与信息系统] TN929.533[电子电信—信息与通信工程]