In this paper, an optimal precoding is designed for multi-cell multi-user MIMO networks. It is proposed to expand a block diagonalization method of single cell to the multi-cell situation. Considering interference leakage to out-of-cell users, a channel projection based block diagonalization (BD) method is used in designing the precoding. Using the extra-space freedom degree offered on the transmitting side, the transmit signal is preprocessed with a cell-based signal-to-leakage-plus-noise ratio (SLNR) maximization criterion, which can compromise the target user signal and leakage interference to suppressed interference. Moreover, a traditional subspace zero forcing procedure is proceeded to mitigate the interference among intra-cell users. Thus,
negative factors of the inter-cell interference for the multi-user MIMO system can be suppressed. Compared to the classical interference leakage zero forcing algorithm, it can flexibly adjust the freedom for inter-cell interference suppression, balance relationship between interference suppression and system capacity enhancement. Moreover, under the same interference, the capacity can be doubled. Both theoretical analysis and simulation
indicate that the proposed methods can efficiently suppress interference while keeping low complexity without changing topology of the current systems.
YANG Ding-cheng1, HE Hao2
. Design of Block Diagonalization Precoding in Multi-cell Multi-user MIMO Network Using Channel Projection[J]. Journal of Applied Sciences, 2014
, 32(4)
: 385
-393
.
DOI: 10.3969/j.issn.0255-8297.2014.04.008
[1] ANDREWS J G, CHOI Wan, HEATH R W. Overcoming interference in spatial multiplexing MIMO cellular networks[J]. IEEE Wireless Communications, 2007, 14(6): 95-104.
[2] GESBERT D, HANLY S, HUANG H, etc. Multi-cell MIMO cooperative networks: a new look at interference [J]. IEEE Journal on Selected areas on Communications [J], 2010, 28(9) : 1380-1408.
[3] YOSHIMOTO A, HATTORI T. Prediction of area capacity in a multilink mimo cellular network with guaranteed QoS [C]//IEEE Wireless Communication and Networking Conference,2007: 1264-1269.
[4] LE-NAM Tran, JUNTTI M, BENGTSSON M, etc. Weighted sum rate maximization for mimo broadcast channels using dirty paper coding and zero-forcing methods [J]. IEEE Transactions on Communications, 2013, 61(6): 2362-2373.
[5] LE-NAM Tran, JUNTTI M, BENGTSSON M, etc. Beamformer designs for MISO broadcast channels with zero-forcing dirty paper coding [J]. IEEE Transactions on Wireless Communications, 2013, 12(3): 1173-1185.
[6] ZHANG H Y, DAI H Y. Cochannel interference mitigation and cooperative processing in downlink multicell multiuser MIMO networks [J]. EURASIP Journal on wireless communications and networking, 2004, 4(2): 222-235.
[7] JIE Tang, LAMBOTHARAN S. Interference alignment techniques for MIMO multi-cell interfering broadcast channels [J]. IEEE Transactions on Communications, 2013, 61(1):164-175.
[8] NIU Bing Lai, WONG V W S, SCHOBER R. Downlink scheduling with transmission strategy selection for multi-cell MIMO systems. [J]. IEEE Transaction on wireless Communications, 2013, 12(1): 736-747.
[9] NGUYEN D H N, DUY H N, LE-HGOC Tho. Block diagonalization precoding game in a multi-user multi-cell system [C]//IEEE Wireless Communications and Networking Conference (WCNC), 2013: 3185-3190.
[10] 杨鼎成，何浩. 多小区 MU-MIMO 系统中基于泄露干扰的分布式块对角化预编码设计[J]. 信号处理，2013, 29(11): 1575-1583.
YANG Dingcheng, HE Hao. Distributed precoding design in multi-cell multi-user MIMO network based on leakage zero forcing block diagonalization [J]. Journal of Signal Processing, 2013, 29(11): 1575-1583. (in Chinese)
MEYER C D. Matrix analysis and applied linear algebra [M]. Philadelphia: Society for Industrial and Applied Mathematics, 2000.
[11] ZHANG H, MEHA N B, MOLISH A F, ZHANG J, DAI H. Asynchronous interference mitigation in cooperative base station systems [J]. IEEE Transactions on Wireless communications, 2008, 7(1): 155-165.
[12] JING S, TSE D N C, SORIAGA J B, HOU J, SMEE J E, PADOVANI R. Multicell downlink capacity with coordinated processing [J]. EURASIP Journal of Wireless Communication and Networking, 2008, 8(2): 1-19.
[13] SOMEKH O , SIMEONE O, BAR-NESS Y, HAIMOVICH A M， SHAMAI S. Cooperative multicell zero-forcing beamforming in cellular downlink channels [J]. IEEE Transactions on Information Theory, 2009, 55(7): 3206-3219.
[14] NG B L, EVANS J S, HANLY S V, AKTAS D. Distributed downlink beamforming with cooperative base stations[J]. IEEE Transaction on Information Theory, 2008, 54(12): 5491-5499.
