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

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

A Pilot-Tone Based Channel Estimation Technique for Cooperative SFBC-OFDM Systems

Cooperative SFBC-OFDM 시스템을 위한 파일럿 톤 기반의 채널 추정 기법

  • 박창환 (중앙대학교 전자전기공학부 디지탈통신연구실) ;
  • 고요한 (중앙대학교 전자전기공학부 디지탈통신연구실) ;
  • 이희수 (한국전자통신연구원) ;
  • 조용수 (중앙대학교 전자전기공학부 디지탈통신연구실)
  • Published : 2008.09.30
Download PDF
⟨ Previous Next ⟩

Abstract

In this paper, a channel estimation technique based on pilot tones is proposed for cooperative SFBC-OFDM systems with a STO(Symbol Timing Offset). In a cooperative SFBC-OFDM system, the STO between RS(Relay Station) and MS(Mobile Station) varies depending on the location of MS. Since the STO causes distortion in the form of phase rotation, a channel estimation technique based on linear interpolation with respect to phase and amplitude is proposed for the case of orthogonal pilot allocation. Also, a channel estimation technique is proposed by solving nonlinear equation for the case of pilot structure with orthogonal code. It is shown by computer simulation that the performance of channel estimation can be significantly improved when the proposed techniques are applied to cooperative SFBC-OFDM systems with STO.

본 논문에서는 STO(Symbol Timing Offset)를 갖는 cooperative SFBC-OFDM 시스템에 적합한 파일럿 톤 기반의 채널 추정 기법을 제안한다. Cooperative SFBC-OFDM 시스템에서는 MS(Mobile Station)의 위치에 따라 RS(Relay Station)와 MS간 STO가 다르게 발생하며 이 STO가 위상 회전 형태로 왜곡을 발생시키기 때문에 orthogonal 파일럿 사용시 위상과 크기에 대하여 선형 보간을 취하여 채널을 추정하는 방법을 제안한다. 또한 orthogonal code를 사용하는 파일럿 구조에서는 비선형 방정식의 해를 구함으로써 채널 추정을 수행하는 방법을 제안한다. STO를 갖는 cooperative SFBC-OFDM 시스템에서 제안된 기법을 적용할 경우에 채널 추정 성능이 크게 개선될 수 있음을 모의실험을 통하여 확인한다.

Keywords

References

  1. [Online] Available : http://www.ieee802.org/16/relay/index.html
  2. A. Sendonaris, E. Erkip, and B. Aazhang, "User cooperation diversity-Part I: System description," IEEE Trans. Commun., Vol.51, No.11, pp.1927-1938, Nov. 2003 https://doi.org/10.1109/TCOMM.2003.818096
  3. A. Sendonaris, E. Erkip, and B. Aazhang, "User cooperation diversity-Part II: Implementation aspects and performance analysis," IEEE Trans. Commun., Vol.51, No.11, pp.1939-1948, Nov. 2003 https://doi.org/10.1109/TCOMM.2003.819238
  4. A. Nosratinia, T. E. Hunter, and A. Hedayat, "Cooperative communication in wireless networks," IEEE Commun. Mag., Vol.42, No.10, pp.74-80, Oct. 2004 https://doi.org/10.1109/MCOM.2004.1341264
  5. J. N. Laneman, D. N. C. Tse, and G.W.Wornell, "Cooperative diversity in wireless networks: Efficient protocols and outage behavior," IEEE Trans. Inf. Theory, Vol.50, No.12, pp.3062-3080, Dec. 2004 https://doi.org/10.1109/TIT.2004.838089
  6. P. Mitran, H. Ochiai, and V. Tarokh, "Space-time diversity enhancements using space-time collaboration," IEEE Trans. Inf. Theory, Vol.51, No.6, pp.2041-2057, Jun. 2005 https://doi.org/10.1109/TIT.2005.847731
  7. H. Ochiai, P. Mitran, and V. Tarokh, "Design and analysis of collaborative diversity protocols for wireless sensor networks," in Proc. IEEE Veh. Technol. Conf.-Fall, Los Angeles, CA, pp.4645-4649., Sep. 2004
  8. O. S. Shin, M. C. Albert, H. T. Kung, and Vahid Tarokh, "Design of an OFDM Cooperative Space-Time Diversity System," IEEE Veh. Technol., Vol.56, No.4, pp.2203-2215, July 2007 https://doi.org/10.1109/TVT.2007.897642
  9. R. U. Nabar, H. Bölcskei, and F. W. Kneubühner, "Fading relay channels: Performance limits and space-time signal design," IEEE J. Sel. Areas Commun., Vol.22, No.6, pp.1099-1109, Aug. 2004 https://doi.org/10.1109/JSAC.2004.830922
  10. D. L. Goeckel and Y. Hao, "Space-time coding for distributed antenna arrays," in Proc. IEEE Int. Conf. Commun., Paris, France, pp.747-751., Jun. 2004
  11. C. R. N. Athaudage and A. D. S. Jayalath, "Enhanced MMSE channel estimation using timing error statistics for wireless OFDM systems," IEEE Transactions on Broadcasting, Vol.50, pp.369-376, Dec. 2004 https://doi.org/10.1109/TBC.2004.837861
  12. I. S. Gradshteyn and I. M. Ryzhik "Jacobian Determinant," $\S$14.313 in Tables of Integrals, Series, and Products, 6th ed. San Diego, CA: Academic Press, pp.1068-1069, 2000
  13. S. M. Alamouti, "A simple transmit diversity technique for wireless communications," IEEE J. Sel. Areas Commnun., Vol.16, No.10, pp.1451-1458, Oct. 1998 https://doi.org/10.1109/49.730453
  14. M. Hsieh and C. Wei, "Channel estimation for OFDM systems based on comb-type pilot arrangement in frequency selective fading channels," IEEE Trans. Consumer Electron. Vol.44, No.1, Feb. 1998