C. Windpassinger, R. F. H. Fisher, T. Vencel, and J. B. Huber, “Precoding in multiantenna and multiuser communications,” IEEE Trans. Wireless Communications, Vol. 3, No. 4, 2004, pp. 1305-1316. doi:10.1109/TWC.2004.830852
 C. B. Ribeiro, K. Hugl, M. Lampinen and M. Kuusela, “Performance of Linear Multi-user MIMO Precoding in LTE System,” Wireless Pervasive Computing, 2008. ISWPC 2008. 3rd International Symposium on, 7-9 May 2008, pp. 410-414.
 M. Joham, W. Utschick and J. A. Nossek, “Linear Transmit Processing in MIMO Communications Systems,” IEEE Transactions Signal Process., Vol. 53, No. 8, 2005, pp. 2700-2712. doi:10.1109/TSP.2005.850331
 C. B. Peel, B. M. Hochwald and A. L. Swindlehurst, “A Vector-perturbation Technique for Near-capacity Multian-tenna Multiuser Communication—Part I: Channel Inversion and Regularization,” IEEE Transactions Communications, Vol. 53, No. 1, 2005, pp. 195-202. doi:10.1109/TCOMM.2004.840638
 Q. H. Spencer, A. L. Swindlehurst and M. Haardt, “Zero-forcing Methods for Downlink Spatial Multiplexing in Multiuser MIMO Channels,” IEEE Transactions Signal. Processing, Vol. 52, No. 2, 2004, pp. 461-471. doi:10.1109/TSP.2003.821107
 M. Sadek, A. Tarighat and A. H. Sayed, “A Leakage-based Precoding Scheme for Downlink Multi-user MIMO Channels,” IEEE Transactions Wireless Communications, Vol. 6, No. 5, 2007, pp. 1711-1721. doi:10.1109/TWC.2007.360373
 A. Tarighat, M. Sadek and A. H. Sayed, “A Multi User Beam-forming Scheme for Downlink MIMO Channels Based on Maximizing Signal-to-leakage Ratios,” in Proc. IEEE Int. Conf. Acoust., Speech, Signal Process., Philadelphia, PA, Mar. Vol. 3, 2005, pp. 1129 -1132.
 H. Yu, J. C. Shin and S.-k. Lee, “Multi-user MIMO Downlink Beamforming Based on Perturbation Theory of Generalized Eigenvector,” Wireless Communication Systems (ISWCS), 2012 International Symposium on, pp. 141-145, 28-31 Aug. 2012.
 P. Viswanath, D. N. C. Tse and V. Anantharam, “Asymptotically Optimal Waterfilling in Multiple Antenna Multiple Access Channels,” Information Theory, 2000. Proceedings. IEEE International Symposium on, pp. 466, 2000.
 W. Yu, W. Rhee, J. M. Cioffi, “Optimal Power Control in Multiple Access Fading Channels with Multiple Antennas,” Communications, 2001. ICC 2001. IEEE International Conference on, Vol. 2, 2001, pp. 575-579.
 H. Yu, Y. Sung, H. Kim and Y. H. Lee, “Beam Tracking for Interference Alignment in Slowly Fading MIMO Interference Channels: A Perturbations Approach Under a Linear Framework,” Signal Processing, IEEE Transactions on, Vol. 60, No. 4, 2012, pp. 1910-1926.