Qualcomm Incorporated, LTE advanced: heterogeneous networks, Feb. 2010. Availalbe: http://www.qualcomm.co.kr/documents/lteadvanced-heterogeneous-networks.
 E. Dahlman, S. Parkvall and J. Skold, “4G: LTE/LTE-advanced for Mobile Broadband,” Academic Press, 2011.
 3GPP Tdoc R4-083018, Qualcomm Europe, Range Expansion for Efficient Support of Heterogeneous Networks, Aug., 2008.
 Y. Wang, K. I. Pedersen, T. B. Sorensen and P. E. Mogensen, “Carrier Load Balancing and Packet Scheduling for Multi-carrier Systems,” IEEE Transactions Wireless Communications, Vol. 9, 2010, pp. 1780-1789. doi:10.1109/TWC.2010.05.091310
 Y. Yan, A. X. Li and X. Y. Gao, “Hidetoshi Kayama, A New Autonomous Component Carrier Selection Scheme for Home eNB in LTE-A System,” in Proceeding IEEE VTC, 2011 Spring, May 2011.
 K. I. Pedersen, F. Frederiksen, C. Rosa and H. Nguyen, Carrier Aggregation for LTE-advanced: Functionality and Performance Aspects, IEEE Communications Magazine, Vol. 49, No. 6, 2011, pp. 89-95. doi:10.1109/MCOM.2011.5783991
 A. Barbieri, P. Gaal, S. Geirhofer, T. Ji, D. Malladi, Y. Wei and F. Xue, “Coordinated Downlink Multi-point Communications in Heterogeneous Cellular Networks,” Information Theory and Applications Workshop (ITA), 2012, pp. 7-16.
 W. Seo, S. Choi and D. Hong, “A Beam-forming Codebook Restriction for Cross-Tier Interference Coordination in Two-Tier Femtocell Networks,” IEEE Transactions on Vehicular Technology, Vol. 60, No. 4, pp. 1651-166.
 W. Yu and R. Lui, “Dual Methods for Nonconvex Spectrum Optimization of Multi-carrier Systems, IEEE Transactions Communications, Vol. 54, No. 7, 2006, pp. 1310-1322. doi:10.1109/TCOMM.2006.877962
 K. M. Ho Zuleita, M. Kaynia and D. Gesbert, Distributed Power Control and Beamforming on MIMO Interference Channels, Wireless Conference (EW), European, April 2010, pp. 654-660.
 P. M. Pardalos and H. E. Romeijn, Handbook of Global Optimization Volume 2 (Noncon-vex Optimization and Its Applications), 1 Edition, Springer, 2002.