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

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

Orthogonal Frequency Division Multiple Access with Statistical Channel Quality Measurements Part-I: System and Channel Modeling

통계적 채널 Quality 정보를 이용한 직교 주파수분할 다중접속(OFDMA) Part-I: 시스템 및 채널 모델링

  • 윤석현 (단국대학교 전기전자컴퓨터공학부)
  • Published : 2006.02.01
Download PDF
⟨ Previous Next ⟩

Abstract

In this two-part paper, we consider dynamic resource allocation in orthogonal frequency division multiple access(OFDMA). To reduce the reverse link overhead for channel quality information(CQI) feedback, a set of sub-carriers are tied up to a sub-channel to be used as the unit of CQI feedback, user-multiplexing and the corresponding power/rate allocation. Specifically, we focus on two sub-channel structures, either aggregated or distributed, where the SNR distribution over a sub-channel is modeled as Ricean in general, and the channel quality of a sub-channel is summarized as the mean and variance of channel gain envelop divided by noise standard deviation. Then, we develop a generalized two step channel/resource allocation algorithm, which uses the two statistical measurements, and analyze the spectral efficiency of the OFDMA system in terms of average frequency utilization. An extension to proportional fair algorithm will also be addressed. As confirmed by numerical results, the aggregated structure is preferred especially when intending aggressive link adaptation.

Part-I과 II를 포함하는 본 연구에서는 하향링크 직교 주파수분할 다중접속(OFDMA) 방식을 위한 실제적인 동적 채널할당 방법에 대해 논의한다. OFDMA 시스템은 채널의 상태정보 궤환을 위한 상향링크에서의 오버헤드를 줄이기 위해 부반송파들의 집합을 하나의 부채널로 정의하고 이를 채널의 상태정보 궤환, 사용자 다중화 및 전력/부호화율 할당의 단위로 사용하는데 본 논문(part-I)에서는 부채널의 일반화된 형태로 연속구조와 분산구조를 정의하고 이들 각 부채널구조의 통계적 특성을 살펴본다. 특히, 각 구조에 대해 부채널상에서의 신호대 잡음비(SNR) 분포를 라이스 분포로 모델링함으로써 각 부채널의 채널 상태를 채널이득의 순시 평균 및 분산의 1, 2차 모멘트로 나타내고 주어진 다중경로 채널 모델에 대해 이 두 파라미터 값의 확률 분포를 유도한다. 본 논문의 결과는 part-II에서 라이스 모델링에 기초한 일반화된 동적자원할당 알고리즘을 제시하고 성능분석을 수행하는데 사용된다.

Keywords

References

  1. T. M. Cover, Elements in Information Theory, Wiley Interscience, 1991
  2. W. Hirt and J.L. Messey, Capacity of the Discrete-Time Gaussian Channel with Intersymbol Interference, IEEE Trans. on Information Theory, Vol.34, No.3, pp.380-388, May 1988
  3. G. Strang, Linear Algebra and its Applications, 1989
  4. P.S. Chow and J.M. Cioffi, Bandwidth optimization for high speed data transmission over channels with severe intersymbol interference, Proc. of Globecom 1992. Vol.1, pp. 59-63, Dec.6-9, 1992
  5. P.S. Chow, J.M. Cioffi and J.A.C. Bingham, A practical discrete multitone transceiver loading algorithm for data transmission over spectrally shaped channels, IEEE Trans. on Comm., Vol.43, No.234, pp.773-775, Feb./March/April 1995 https://doi.org/10.1109/26.380108
  6. J. Campello, Discrete Bit Loading for Multicarrier Modulation Systems, Ph.D. dissertation, Stanford, 1999
  7. A. Goldsmith and P. Varaiya, Increasing spectral efficiency through power control, Proc. of ICC'93, pp. 600-604, June 1993
  8. A. Goldsmith and S. Chua, Variable-Rate Variable-Power MQAM for Fading Channels, IEEE Trans. on Comm., Vol.45, No. 10, pp.1218-1230, Oct. 1997 https://doi.org/10.1109/26.634685
  9. A. Goldsmith and S. Chua, Adaptive Coded Modulation for Fading Channels, IEEE Trans. on Comm., Vol.46, No.5, pp.595-602, May 1998 https://doi.org/10.1109/26.668727
  10. R. Knopp and P.A. Humblet, Multiple Accessing over Frequency Selective Channels, Proc. of PIMRC'95, pp.1326-1330
  11. C. Y. Wong, R. S. Cheng, K. B. Letaief and R. D. Murch, Multiuser OFDM with Adaptive Subcarrier, Bit and Power Allocation, IEEE JSAC, Vol.17, No. 10, pp.1747-1758, Oct. 1999
  12. H. Yin, H. Liu, 'An efficient multiuser loading algorithm for OFDM-based broadband wireless systems,' Proc. of Globecom'00, Vol.1, pp.103-107, San Francisco, USA, 2000
  13. S. Pfletschinger, G. Mnz, J. Speidel, 'Efficient Subcarrier Allocation for multiple access in OFDM Systems', Proc. of 7th International OFDM-Workshop, pp.21-25, Sep. 2002, Hamburg
  14. W. Rhee and J.M. Cioffi, Increase in Capacity of Multiuser OFDM System Using Dynamic Sub-Channel Allocation, Proc. of VTC'00-Spring, Vol.2, pp.15-18 May 2000
  15. J. Jang and K. Lee, Transmit Power Adaptation for Multiuser OFDM Systems, IEEE Journal on Selected Areas in Communications, Vol.21, No.2, pp.171-178, Feb. 2003 https://doi.org/10.1109/JSAC.2002.807348
  16. 조용수, 휴대인터넷 무선접속 표준 기술, TTA저널 제93호, TTA, 2004. 6
  17. IEEE Standard for Local and Metropolitan Area Networks--Part 16: Air Interface for Fixed Broadband Wireless Access Systems, http://standards.ieee.org/getieee802/
  18. 3GPP TSG-RAN, TR25.892 v1.1.0, Feasibility Study for Enhanced Uplink for UTRA, March 2004