|| A. Damnjanovic, et al., “A survey on 3GPP heterogeneous networks,” IEEE Wireless Commun., vol.18, no.3, pp.10-21, Jun. 2011.|
 A. Khandekar, N. Bhushan, J. Tingfang and V. Vanghi, “LTE-Advanced: Heterogeneous networks,” Wireless Conference (EW), pp.978-982, April 2010.
 T. Hu, J. Pang, H.-J. Su, “LTE-Advanced heterogeneous networks: Release 10 and beyond,” in Proc. IEEE Int. Conf on Comm (ICC), Jun. 2012.
 E. Bodanese. “A brief introduction to heterogeneous networks (Hetnets) and its challenges,” in IET international conference, 2011, pp. 605-609, Oct. 2011.
 A. B. Saleh et al., “Comparison of Relay and Pico eNB Deployments in LTE-Advanced,” in Proc. IEEE Vehicular Technology Conference Fall (VTC), pp.1-5, Sept. 2009.
 Q. Liu and Z. Song, “Design of Picocells in Heterogeneous Networks, ” in Proc. Measuring Technology and Mechatronics Automation , Fifth International Conference, pp.452-455, Jan. 2013.
 M. W. Arshad, A. Vastberg and T. Edler, “Energy efficiency gains through traffic offloading and traffic expansion in joint macro pico deployment,” in Proc. IEEE Wireless Communications and Networking Conference, pp.2203-2208, April 2012.
 R. Torrea-Duran, C. Desset, S. Pollin and A. Dejonghe, “Adaptive energy efficient scheduling algorithm for LTE pico base stations, ” Future Network & Mobile Summit, pp.1-8, July 2012.
 J. Lee, R.V. Sonalkar, J. M. Cioffi, “Multiuser bit loading for multicarrier systems,” IEEE Trans. Commun., vol.54, no.7, pp.1170-1174, July 2006.
 A. Garg and A. K. Chaturvedi, “A hybrid time divisioning scheme for power allocation in DMT-based DSL systems,” IEEE Communications Letters, vol.10, no.2, pp.73-75, Feb. 2006.
 M. C. Akujuobi and J. Shen, “Efficient Multi-User Parallel Greedy Bit-Loading Algorithm with Fairness Control For DMT Systems,” The Center of Excellence for Communication Systems Technology Research, Prairie View A&M University, Prairie View, Texas 77446, USA.
 J. Lee, R. V. Sonalkar and J. M. Cioffi, “A multi-user rate and power control algorithm for VDSL, ” in Proc. IEEE Gloobecom, vol.2, pp.1264-1268, Nov. 2002
 J. Lee, R. V. Sonalkar and J. M. Cioffi, “Multi-user Discrete Bit-loading for DMT-based DSL systems,” in Proc. IEEE Gloobecom, vol. 2, pp. 1259-1263, Nov. 2002.
 D. Wang, Y. Cao, L. Zheng, Z. Du, “Iterative Group-by-Group Bit-Loading Algorithms for OFDM Systems,” IEEE Trans. Veh. Technol., vol.62, no.8, pp.4131-4135, Oct. 2013.
 D. Lopez-Perez, A. Valcarce, G. de la Roche and G. J. Zhang, “OFDMA femtocells: A roadmap on interference avoidance,” IEEE Communications Magazine, vol.47, no.9, pp.41-48, Sept.2009.
 W. C. Pao, Y. F. Chen, and C. Y. Chan, “Power allocation schemes in OFDM-based femtocell networks,” Wireless Pers. Commun., vol. 69, no. 4, pp. 1165–1182, Apr. 2013.
 W. C. Pao, Y. F. Lu, C. Y. Shih and Y. F. Chen, “Genetic Algorithm-Based Power Allocation for Multiuser MIMO-OFDM Femtocell Networks with ZF Beamforming, ” in Proc. IEEE Vehicular Technology Conference Fall (VTC) , pp.1-5, Sept. 2013.
 S. Jaturong, S. Yuya, M. Nobuhiko, A. Tetsushi, N. Satoshi and O. Yukihiko, “Investigation on Cell Selection Methods Associated with Inter-cell Interference Coordination in Heterogeneous Networks for LTE-Advanced Downlink, ” in Proc. Wireless Conference 2011 - Sustainable Wireless Technologies, pp.1-6, April 2011.
 N. Papandreou and T. Antonakopoulos, “A new computationally efficient discrete bit-loading algorithm for DMT applications,” IEEE Trans. Commun., vol.53, no.5, pp.785-789, May 2005.
 H. Ko, K. Lee, S. Oh, and C. Kim, “Fast Optimal Discrete Bit-Loading Algorithms for OFDM-based systems,” in proceeding of International Conference on Computer Commun. and Networks (ICCCN), pp. 1-6, Aug. 2009.
 K. S. Al-Mawali, A. Z. Sadik, Z. M. Hussain, “Simple discrete bit-loading for OFDM systems in power line communications,” IEEE International Symposium on Power Line Communications and Its Applications, pp.267-270, April 2011.
 Y. Song, D. Wang, M. Li and Y. Yang, “A novel constant-power bit loading algorithm for QAM modulated OFDM systems,” in Proc. IEEE International Conference, Information Theory and Information Security, pp.1042,1045, 17-19 Dec. 2010.
 S. T. Chung; A. J. Goldsmith, “Degrees of freedom in adaptive modulation: a unified view,” IEEE Trans. Commun., vol.49, no.9, pp.1561-1571, Sept. 2001.
 A. Sani and A. Abbasfar, “Qos-aware discrete bit loading for OFDMA networks,” in Proc. Computing, Networking and Communications on International Conference, pp.994-998, Jan. 2013.
 I. Isha, P. Rana and R. Saini, “Performance of Different Bit Loading Algorithms for OFDM at PLC Channel, ” in Proc. Advanced Computing & Communication Technologies on Second International Conference , pp.486-489, Jan. 2012.
 H. Cordova and L. Van Biesen, “A parallel bit removal greedy algorithm for multiuser 4G OFDM-based systems,” in Proc. 22nd IEEE International Symposium on Personal Indoor and Mobile Radio Commun. (PIMRC’11), pp.1366-1370, Sept. 2011.
 W. C. Pao, Y.F. Chen, M. G. Tsai, “An Adaptive Allocation Scheme in Multiuser OFDM Systems with Time-Varying Channels, ” IEEE Trans. Commun., vol.13, no.2, pp.669-679, Feb. 2014.
 J. G. Proakis, “Digital Communication,” New York, McGraw-Hill, 2001.
 S. U. Pillai, T. Suel, and S. Cha, “The Perron-Frobenius theorem: some of its applications,” IEEE Signal Processing Magazine, Vol. 22, no. 2, pp. 62–75, Mar 2005.
 Evolved Universal Terrestrial Radio Access (E-UTRA); Further advancements for E-UTRA physical layer aspects (Release 9), 3GPP, TS 36.814 V9.0.0, Mar. 2010.
 Evolved Universal Terrestrial Radio Access (E-UTRA); Mobility enhancements in heterogeneous networks, 3GPP TR 36.839 V11.1.0, 2012.