The Journal of Korean Institute of Communications and Information Sciences (한국통신학회논문지)

The Korean Institute of Commucations and Information Sciences (한국통신학회)
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Improved Power Allocation to Enhance the Capacity in OFDMA System for Proportional Resource Allocation

Proportional 자원할당을 위한 OFDMA 시스템에서 채널 용량을 증대시키기 위한 향상된 전력 할당 기법

  • Var, Puthnith (Wireless Transmission Lab, The Graduate School of Information Technology & Telecommunications, Inha University) ;
  • Shrestha, Robin (Wireless Transmission Lab, The Graduate School of Information Technology & Telecommunications, Inha University) ;
  • Kim, JaeMoung (Wireless Transmission Lab, The Graduate School of Information Technology & Telecommunications, Inha University)
  • Received : 2012.02.24
  • Accepted : 2013.07.09
  • Published : 2013.07.31
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Abstract

The Orthogonal Frequency Division Multiple Access (OFDMA) is considered as a novel modulation and multiple access technique for 4th generation wireless systems. In this paper, we formulate a base station's power allocation algorithm for each user to maximize the user's sum rate, subject to constraints on total power, bit error rate, and rate proportionality among the users for a better proportional rate adaptive (RA) resource allocation method for OFDMA based system. We propose a novel power allocation method based on the proportion of subcarrier allocation and the user's normalized proportionality constant. We adapt a greedy algorithm and waterfilling technique for allocating the subcarriers among the users. In an end-to-end simulation, we validate that the proposed technique has higher system capacity and lower CPU execution times, while maintaining the acceptable rate proportionality among users.

Orthogonal Frequency Division Multiple Access(OFDMA)는 4세대 무선 통신을 위해 고려되는 변조와 다중 접속 기술이다. 본 논문에서는, OFDMA 시스템에서 더 나은 proportional rate의 자원할당 기법을 위해 전체 전력, 비트 오류율, 유저 간의 rate proportionality에 대한 제한 조건을 만족시키면서, 유저의 전송률을 최대화 시키는 전략 할당 알고리즘에 대해 기술하였다. 그리고 subcarrier 할당의 비율과 유저의 정규화된 proportionality 조건에 기반을 둔 전력 할당 방식을 제안하였다. 유저에게 subcarrier 할당을 위한 방법으로는 greedy 알고리즘과 waterfilling 기술이 적용되었다. 제안된 알고리즘에 대한 평가는 시뮬레이션을 통해서 이루어졌으며, 시뮬레이션을 통해서 제안된 알고리즘이 유저 간의 rate proportionality를 유지하면서 더 높은 시스템 채널 용량과 적은 소요 시간을 보인다는 것을 확인할 수 있었다.

Keywords

References

  1. L. J. Cimini, "Analysis and simulation of a digital mobile channel using orthogonal frequency division multiplexing," IEEE Trans. Commun., vol. 33, no. 7, pp. 665-675, July 1985. https://doi.org/10.1109/TCOM.1985.1096357
  2. R. V. Nee and R. Prasad, OFDM for Wireless Multimedia Communications. Norwood, MA, USA: Artech House, 2000.
  3. S. Hara and R. Prasad, Multicarrier Techniques for 4G Mobile Communications. Norwood, MA, USA: Artech House, 2003.
  4. D. Lee, S. Im, H. Roh, and H. Choi, "Frequency synchronization algorithm for improving performance of OFDMA system in 3GPP LTE downlink," J. Korean Inform. Commun. Soc. (KICS), vol. 34, no. 1C, pp. 120-130, Jan. 2009.
  5. C. Y. Wong, R. S. Cheng, K. B. Lataief, and R. D. Murch, "Multiuser OFDM with adaptive subcarrier, bit, and power allocation," IEEE J. Sel. Areas in Commun., vol. 17, no. 10, pp. 1747-1758, Oct. 1999. https://doi.org/10.1109/49.793310
  6. J. Jang and K. B. Lee, "Transmit power adaptation for multiuser OFDM systems," IEEE J. Sel. Areas in Commun., vol. 21, no. 2, pp. 171-178, Feb. 2003. https://doi.org/10.1109/JSAC.2002.807348
  7. H. Yin and H. Liu, "An efficient multiuser loading algorithm for OFDM-based broadband wireless systems," in Proc. IEEE Global Telecommun. Conf. (GLOBECOM '00), pp. 103-107, San Francisco, U.S.A., Nov.-Dec. 2000.
  8. W. Rhee and J. M. Cioffi, "Increase in capacity of multiuser OFDM system using dynamic subchannel allocation," in Proc. IEEE 51st Veh. Technol. Conf. (VTC 2000-Spring), pp. 1085-1089, Tokyo, Japan, May 2000.
  9. Z. Shen, J. G. Andrews, and B. L. Evans, "Optimal power allocation in multiuser OFDM systems," in Proc. IEEE Global Telecommun. Conf. (GLOBECOM '03), pp. 337-341. San Francisco, U.S.A., Dec. 2003.
  10. I. C. Wong, Z. Shen, B. L. Evans, and J. G. Andrews, "A low complexity algorithm for proportional resource allocation in OFDMA systems," in Proc. IEEE Workshop Signal Process. Syst. (SIPS 2004), pp. 1-6, Austin, U.S.A., Oct. 2004.
  11. A. Falahati and M. R. Ardestani, "An improved low-complexity resource allocation algorithm for OFDMA systems with proportional data rate constraint," in Proc. 9th Int. Conf. Advanced Commun. Tech., pp. 606-611, Gangwon-Do, Korea, Feb. 2007.
  12. J. Leinonen, J. Hamalainen, and M. Juntti, "Performance analysis of downlink OFDMA resource allocation with limited feedback," IEEE Trans. Wireless Commun., vol. 8, no. 6, pp. 2927-2937, June 2009. https://doi.org/10.1109/TWC.2009.071374
  13. Y. Hu and L. Li, "A low-complexity resource allocation algorithm based on proportional fairness for multiuser OFDM systems," in Proc. 4th Int. Conf. Wireless Commun. Networking Mobile Comput. (WiCOM '08), pp. 1-4, Dalian, China, Oct. 2008.
  14. J. F. Schmidt, J. E. Cousseau, R. Wichman, and S. Werner, "Bit loading using imperfect CSIT for prediction-based resource allocation in mobile OFDMA," IEEE Trans. Veh. Technol., vol. 60, no. 8, pp. 4082-4088, Oct. 2011. https://doi.org/10.1109/TVT.2011.2165305
  15. S. T. Chung and A. Goldsmith, "Degrees of freedom in adaptive modulation: a unified view," IEEE Trans. Commun., vol. 49, no. 9, pp. 1561-1571, Sep. 2001. https://doi.org/10.1109/26.950343