下行多用户MIMO系统中的一种联合处理算法
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摘要
在多用户下行多输入多输出(MIMO)系统中,采用空分多址(SDMA)技术能提高系统的吞吐量。然而,在多用户下行MIMO系统中存在共信道干扰问题,很大程度上影响了整个系统的实际容量。因此,提出了一种联合处理算法,即将块对角化(BD)算法与最小均方误差(MMSE)算法相结合,对信号进行联合处理,以降低共信道干扰。仿真验证表明,所提算法有效降低了共信道干扰,提高了系统性能,算法具有有效性。
SDMA(Space-Division Multiple Access) is adopted in the downlink of a multiuser multiple-input multiple-output(MIMO) wireless communication system, so as to raise the system throughput. However, there exists the co-channel interference in the multi-user downlink of MIMO wireless communication system, and this would affect the actual capacity of the whole system to a large extent. In order to reduce the co-channel interference, a combined processing algorithm is proposed for uplink multiuser MIMO system, that is, the signal is co-processed by combining BD(Block Diagonalization) algorithm with MMSE(Minimal Mean-Square Error) algorithm. The proposed algorithm could efficiently reduce the co-channel interference and improves the system performances. Simulation indicates the effectiveness of the proposed algorithm.
SDMA(Space-Division Multiple Access) is adopted in the downlink of a multiuser multiple-input multiple-output(MIMO) wireless communication system, so as to raise the system throughput. However, there exists the co-channel interference in the multi-user downlink of MIMO wireless communication system, and this would affect the actual capacity of the whole system to a large extent. In order to reduce the co-channel interference, a combined processing algorithm is proposed for uplink multiuser MIMO system, that is, the signal is co-processed by combining BD(Block Diagonalization) algorithm with MMSE(Minimal Mean-Square Error) algorithm. The proposed algorithm could efficiently reduce the co-channel interference and improves the system performances. Simulation indicates the effectiveness of the proposed algorithm.
引文
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[2]Lau V K N,Zhang F,Cui Y.Low Complexity Delay-constrained Beamforming for Multi-user MIMO Systems with Imperfect CSIT[J].Signal Processing,IEEE Transactions on,2013,61(16):4090-4099.
[3]Costa M H M.Writing on Dirty Paper(Corresp.)[J].I n f o r m a t i o n T h e o r y,I E E E T r a n s a c t i o n s on,1983,29(03):439-441.
[4]Yoo T,Goldsmith A.On the Optimality of Multiantenna B r o a d c a s t S c h e d u l i n g U s i n g Z e r o-f o r c i n g Beamforming[J].Selected Areas in Communications,IEEE Journal on,2006,24(03):528-541.
[5]Wang J,Yao K.Multiuser Spatio-temporal Coding for Wireless Communications[C].Wireless Communications and Networking Conference,2002:276-279.
[6]Su W,Matyjas J D,Gans M J,et al.Maximum Achievable Capacity in Airborne MIMO Communications with Arbitrary Alignments of Linear Transceiver Antenna Arrays[J].Wireless Communications,IEEE Transactions on,2013,12(11):5584-5593.
[7]Spencer Q H,Swindlehurst A L,Haardt M.Zero-forcing Methods for Downlink Spatial Multiplexing in Multiuser MIMO Channels[J].Signal Processing,IEEE Transactions on,2004,52(02):461-471.
[8]Shen Z,Chen R,Andrews J G,et al.Sum Capacity of Multiuser MIMO Broadcast Channels with Block Diagonalization[J].Wireless Communications,IEEE Transactions on,2007,6(6):2040-2045.
[9]Chatzinotas S.MMSE Filtering Performance of Dual-Hop Amplify-and-Forward Multiple-Access Channels[J].Wireless Communications Letters,2013,2(01):122-125.
[10]Madhow U,Honig M L.MMSE Interference Suppression for Direct-sequence Spread-spectrum CDMA[J].Communications,IEEE Transactions on,1994,42(12):3178-3188.
[11]Raleigh G C,Cioffi J M.Spatio-temporal Coding for Wireless Communication[J].Communications,IEEE Transactions on,1998,46(03):357-366.
[12]Foschini G J,Gans M J.On Limits of Wireless Communications in a Fading Environment When Using Multiple Antennas[J].Wireless Personal Communications,1998,6(03):311-335.
[13]Boyd S P,Vandenberghe L.Convex Optimization[M].Cambridge:Cambridge University Press,2004.
[14]van de Beek J J,Edfors O,Sandell M,et al.On Channel Estimation in OFDM Systems[C].Proceedings of IEEE Vehicular Technology Conference(VTC95),1995(02):815-819.
[15]Jing Y,Yu X.ML-based Channel Estimations for Non-regenerative Relay Networks with Multiple Transmit and Receive Antennas[J].Selected Areas in Communications,IEEE Journal on,2012,30(08):1428-1439.