Abstract
The paper proposes a scheme to minimize the co-tier and cross-tier interference by properly allocating the sub-channels and power among the femtocell users (FUs) in an OFDMA based cognitive femtocell network. An efficient graph coloring based sub-channel allocation scheme is adapted in which the sub-channels in the uplink band of the macrocell are shared by the femtocells dynamically in an opportunistic way through spectrum sensing. A price-based power allocation scheme using game theory is proposed to assign the transmission power among the FUs, whereby the macrocell base-station (MBS) controls the transmission power of the FUs by pricing their resulted interference power levels at the MBS with the constraint that the total interference created at the MBS in each sub-channel is kept below a tolerable threshold. The game theoretic approach ensures that no FUs can improve its utility by changing its own transmission power selfishly. The allocation of sub-channels among the FUs is centrally controlled whereas the power allocation is handled in a distributed way which makes the process efficient. Finally, numerical examples are presented to analyze the proposed scheme. The results show that substantial number of FUs with good quality of services can be accommodated in the macrocell reusing the uplink frequency sub-channels and thereby enhancing the throughput and coverage of the network.











Similar content being viewed by others
References
Chandrasekhar, V., Andrews, J. G., & Gatherer, A. (2008). Femtocell networks: A survey. IEEE Communication Magazine, 46(9), 59–67.
Claussen, H., Ho, L. T., & Samuel, L. G. (2008). An overview of the femtocell concept. Bell Labs Technical Journal, 13(1), 221–245.
López-Pérez, D., Valcarce, A., De La Roche, G., & Zhang, J. (2009). OFDMA femtocells: A roadmap on interference avoidance. IEEE Communications Magazine, 47(9), 41–48.
Chandrasekhar, V., Andrews, J. G., Muharemovict, T., Shen, Z., & Gatherer, A. (2009). Power control in two-tier femtocell networks. IEEE Transactions on Wireless Communications, 8(8), 4316–4328.
Li, L., Xu, C., & Tao, M. (2012). Resource allocation in open access OFDMA femtocell networks. IEEE Wireless Communications Letters., 1(6), 625–628.
Gupta, N. K., & Banerjee, A. (2011). Power and subcarrier allocation for OFDMA femto-cell based underlay cognitive radio in a two-tier network. In Proceedings internet multimedia systems architecture and application (IMSAA), (pp. 1–6).
Chandrasekhar, V., & Andrews, J. G. (2009). Uplink capacity and interference avoidance for two-tier femtocell networks. IEEE Transactions on Wireless Communications, 8(7), 3498–3509.
Kim, J., & Cho, D. H. (2010). A joint power and subchannel allocation scheme maximizing system capacity in indoor dense mobile communication systems. IEEE Transactions on Vehicular Technology, 59(9), 4340–4353.
Xiang, J., Zhang, Y., Skeie, T., & Xie, L. (2010). Downlink spectrum sharing for cognitive radio femtocell networks. IEEE Systems Journal, 4(4), 524–534.
Sun, Y., Jover, R. P., & Wang, X. (2012). Uplink interference mitigation for OFDMA femtocell networks. IEEE Transactions on Wireless Communications, 11(2), 614–625.
Güvenç, I., Jeong, M. R., Watanabe, F., & Inamura, H. (2008). A hybrid frequency assignment for femtocells and coverage area analysis for co-channel operation. IEEE Communications Letters, 12(12), 880–882.
Ngo, D. T., Le, L. B., & Le-Ngoc, T. (2012). Distributed Pareto-optimal power control for utility maximization in femtocell networks. IEEE Transactions on Wireless Communications, 11(10), 3434–3446.
Tan, C. W., Friedland, S., & Low, S. H. (2011). Spectrum management in multiuser cognitive wireless networks: Optimality and algorithm. IEEE Journal on Selected Areas in Communications, 29(2), 421–430.
Chandrasekhar, V., & Andrews, J. G. (2009). Spectrum allocation in tiered cellular networks. IEEE Transactions on Communications, 57(10), 3059–3068.
Jeong, Y., Quek, T. Q., & Shin, H. (2011). Beamforming optimization for multiuser two-tier networks. Journal of Communications and Networks, 13(4), 327–338.
Jeong, Y., Shin, H., & Win, M. Z. (2011). Interference rejection combining in two-tier femtocell networks. In Proceormation theory and applicationo communications (PIMRC), (pp. 137–141).
Guler, B., & Yener, A. (2014). Selective interference alignment for MIMO cognitive femtocell networks. IEEE Journal on Selected Areas in Communication, 32(3), 439–450.
Ko, C. H., & Wei, H. Y. (2011). On-demand resource-sharing mechanism design in two-tier OFDMA femtocell networks. IEEE Transactions on Vehicular Technology, 60(3), 1059–1071.
Cheng, S. M., Lien, S. Y., Chu, F. S., & Chen, K. C. (2011). On exploiting cognitive radio to mitigate interference in macro/femto heterogeneous networks. IEEE Wireless Communications, 18(3), 40–47.
Adhikary, A., Ntranos, V., & Caire, G. (2011). Cognitive femtocells: Breaking the spatial reuse barrier of cellular systems. In Information theory and applications workshop (ITA), (pp. 1–10).
Kang, X., Zhang, R., & Motani, M. (2012). Price-based resource allocation for spectrum-sharing femtocell networks: A stackelberg game approach. IEEE Journal on Selected Areas in Communications, 30(3), 538–549.
Lee, H., Han, K., Hwang, Y., & Choi, S. (2009). Opportunistic band sharing for point-to-point link connection of cognitive radios. In Proceedings cognitive radio oriented wireless networks and communications (CROWNCOM), (pp. 1–6).
Nash, J. (1951). Non-cooperative games. Annals of Mathematics, 54(2), 286–295.
Saraydar, C. U., Mandayam, N. B., & Goodman, D. (2002). Efficient power control via pricing in wireless data networks. IEEE Transactions on Communications, 50(2), 291–303.
Yates, R. D. (1995). A framework for uplink power control in cellular radio systems. IEEE Journal on Selected Areas in Communications, 13(7), 1341–1347.
Acknowledgments
The work is undertaken as part of Media Lab Asia Project entitled “Mobile Broadband Service Support over Cognitive Radio Networks”.
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Karar, S., Das Barman, A. Opportunistic Sub-channel and Transmit Power Allocation in an OFDMA Based Cognitive Femtocell Network. Wireless Pers Commun 84, 1303–1323 (2015). https://doi.org/10.1007/s11277-015-2689-3
Published:
Issue Date:
DOI: https://doi.org/10.1007/s11277-015-2689-3