Journal of Communications and Networks

The Korean Institute of Commucations and Information Sciences (한국통신학회)
권호 표지
DOI QR코드

DOI QR Code

Power Allocation and Subcarrier Assignment for Joint Delivery of Unicast and Broadcast Transmissions in OFDM Systems

  • Lee, Deokhui (Department of Electronic Engineering, Sogang University) ;
  • So, Jaewoo (Department of Electronic Engineering, Sogang University) ;
  • Lee, Seong Ro (Department of Information and Electronics Engineering, Mokpo National University)
  • Received : 2015.04.20
  • Accepted : 2015.11.23
  • Published : 2016.06.30
⟨ Previous Next ⟩

Abstract

Most existing studies on broadcast services in orthogonal frequency division multiplexing (OFDM) systems have focused on how to allocate the transmission power to the subcarriers. However, because a broadcasting system must guarantee quality of service to all users, the performance of the broadcast service dominantly depends on the channel state of the user who has the lowest received signal-to-noise ratio among users. To reduce the effect of the worst user on the system performance, we propose a joint delivery scheme of unicast and broadcast transmissions in OFDM systems with broadcast and unicast best-effort users. In the proposed joint delivery scheme, the BS delivers the broadcast information using both the broadcast and unicast subcarriers at the same time in order to improve the performance of the broadcast service. The object of the proposed scheme is to minimize the outage probability of the broadcast service while maximizing the sum-rate of best-effort users. For the proposed joint delivery scheme, we develop an adaptive power and subcarrier allocation algorithm under the constraint of total transmission power. This paper shows that the optimal power allocation over each subcarrier in the proposed scheme has a multi-level water filling form. Because the power allocation and the subcarrier assignment problems should be jointly solved, we develop an iterative algorithm to find the optimal solution. Numerical results show that the proposed joint delivery scheme with adaptive power and subcarrier allocation outperforms the conventional scheme in terms of the outage probability of the broadcast service and the sum-rate of best-effort users.

Keywords

Acknowledgement

Supported by : Institute for Information and Communications Technology Promotion (IITP), National Research Foundation of Korea (NRF)

References

  1. F. Hartung et al., "Delivery of broadcast services in 3G networks," IEEE Trans. Broadcast., vol. 52, no. 1, pp. 188-199, Mar. 2007.
  2. G. L. Stuber et al., "Broadband MIMO-OFDMwireless communications," in Proc. IEEE, vol. 92, no. 2, pp. 271-293, Feb. 2004. https://doi.org/10.1109/JPROC.2003.821912
  3. 3GPP, "Physical layer aspects for evolved universal terrestrial radio access (UTRA)," 3GPP, TR 25.812 Ver. 7.1.0, Sept. 2006.
  4. 3GPP, "Requirements for evolved UTRA (E-UTRA) and evolved UTRAN (E-UTRAN)," 3GPP, TR 25.913 Ver. 9.0.0, Dec. 2009.
  5. M. R. Chari et al., "FLO physical layer: An overview," IEEE Trans. Broadcast., vol. 53, no. 1, pp. 145-160, Mar. 2007. https://doi.org/10.1109/TBC.2007.891696
  6. Y. Cai et al., "Reduced feedback schemes for LTEMBMS," in Proc. IEEE VTC, Apr. 2009, pp. 1-5.
  7. K. Sohn, H. Kim, and Y. Kim, "A novel multicast scheme for feedbackbased multicast services over wireless networks," EURASIP J. Wireless Commun. Netw., pp. 1-12, Feb. 2013.
  8. C. Suh and J. Mo, "Resource allocation for multicast services in multicarrier wireless communications," IEEE Trans. Wireless Commun., vol. 7, no. 1, pp. 27-31, Jan. 2008. https://doi.org/10.1109/TWC.2008.060467
  9. S. Kwack, H. Seo, and B. G. Lee, "Suitability-based subcarrier allocation for multicast services employing layered video coding in wireless OFDM systems," in Proc. IEEE VTC, Oct. 2007, pp. 1752-1756.
  10. H. Kwon and B. Lee, "Cooperative power allocation for broadcst/multicast services in cellular OFDM systems," IEEE Trans. Commun., vol. 57, no. 10, pp. 3092-3102, Oct. 2009. https://doi.org/10.1109/TCOMM.2009.10.080196
  11. D. Kim, T. Fujii, and K. Lee, "A power allocation algorithm for maximizing total utility over and MBSFN," IEEE Wireless Commun. Lett., vol. 2, no. 3, pp. 283-286, June 2013. https://doi.org/10.1109/WCL.2013.022213.130017
  12. A. Alexiou, C. Bouras, V. Kokkinos, A. Papazois, and G. Tsichritzis, "Efficient MCS selection for MBSFN transmissions over LTE networks," in Proc. IFIP Wireless Day, Oct. 2010, pp. 1-5.
  13. T. Low, M. Pun, Y. Hong, and C. Kuo, "Optimized opportunistic multicast scheduling (OMS) over wireless cellular networks," IEEE Trans. Wireless Commun., vol. 9, no. 2, pp. 791-801, Feb. 2010. https://doi.org/10.1109/TWC.2010.02.090387
  14. M. Konrad, W. Koch, and J. Huschke, "Throughput based switching threshold for multicast and unicast in cellular OFDM networks," in Proc. IEEE VTC, Sept. 2007, pp. 1927-1931.
  15. J. F. Monserrat, J. Calabuig, A. Fernandez-Aguilella, and D. Gomez-Barquero, "Joint delivery of unicast and E-MBMS services in LTE networks," IEEE Trans. Broadcast., vol. 58, no. 2, pp. 157-167, June 2012. https://doi.org/10.1109/TBC.2012.2191030
  16. A. de la Fuente, A. G. Armada, and R. P. Leal, "Joint multicast/unicast scheduling with dynamic optimization for LTE multicast service," in Proc. EW, May 2014, pp. 1-6.
  17. M. Condoluci et al., "On the management of unicast and multicast services in LTE networks," in Proc. IEEE Int. Symposium BMSB, June 2015, pp. 1-5.
  18. X. Sun, C. Wu, and Z. Zeng, "Dynamic power saving mechanism joint delivery of unicast and E-MBMS services in LTE MBSFN networks," in Proc. IEEE ITSC, Oct. 2013, pp. 189-194.
  19. J. M. Cioffi, Digital communications. Standford, CA: Stanford University, 2013.
  20. R. S. Cheng and S. Verdu, "Gaussian multiaccess channels with ISI: Capacity regions and multiuser water-filling," IEEE Trans. Inf. Theory, vol. 39, pp. 773-785, May 1993. https://doi.org/10.1109/18.256487
  21. C. Y. Wong, R. S. Cheng, K. B. Letaief, and R. D. Murch, "Multiuser OFDM with adaptive subcarrier, bit and power allocation," IEEE J. Sel. Areas Commun., vol. 17, no. 10, pp. 1747-1758, Oct. 1999. https://doi.org/10.1109/49.793310
  22. M. Tao, Y. Liang, and F. Zhang, "Resource allocation for delay differentiated traffic in multiuser OFDM systems," IEEE Trans. Wireless Commun., vol. 7, no. 6, pp. 2190-2201, June 2008. https://doi.org/10.1109/TWC.2008.060882
  23. M. Fadel, A. Ibrahim, and H. Elgebaly, "QoS-aware multi-RAT resource allocation with minimum transmit power in multiuser OFDM system," in Proc. IEEE GLOBECOM Workshops, Dec. 2012, pp. 670-675.
  24. S. Boyd and L. Vandenberghe, Convex Optimization. Cambridge, UK: Cambridge University Press, 2004.
  25. G. Song and Y. G. Li, "Cross-layer optimization for OFDM wireless networks. part ii: Algorithm development," IEEE Trans. Wireless Commun., vol. 4, no. 2, pp. 625-634, Mar. 2005. https://doi.org/10.1109/TWC.2004.843067