OFDMA 스마트 안테나 시스템을 위한 도래각 추정 기반의 적응 빔 형성 알고리즘

A Direction-of-Arrival Estimation Based Adaptive Beamforming Algorithm for OFDMA Smart Antenna Systems

  • 윤영호 (한국항공대학교 항공전자 및 정보통신공학부) ;
  • 박윤옥 (한국전자통신연구원 이동통신연구단 패킷모뎀연구팀) ;
  • 박형래 (한국항공대학교 항공전자 및 정보통신공학부)
  • 발행 : 2006.12.30

초록

본 논문에서는 orthogonal frequency-division multiple-access 스마트 안테나 시스템을 위한 효율적인 도래각 추정 기반의 적응 빔 형성 알고리즘을 제안한다. 제안된 알고리즘은 추정된 도래각 정보를 이용하여 원하는 신호의 방향으로 주 빔 (main beam)을 형성하는 반면, 간섭 신호의 방향에는 null을 형성함으로써 간섭 신호를 효율적으로 제거한다. 또한, 다중 경로 신호에 대한 빔 형성 출력들을 효율적으로 결합함으로써 공간 다이버시티 이득을 얻을 수 있다. 제안된 알고리즘의 효율성을 입증하기 위해 셀룰러 이동통신 환경에서 WiBro 시스템을 목표 시스템 (target system)으로 설정하여 알고리즘의 성능을 분석하고 least-sqaures 빔 형성 알고리즘과 성능을 비교한다.

In this paper, an efficient direction-r)f-arrival based adaptive beamforming algorithm for orthogonal frequency-division multiple-access smart antenna systems is proposed. The proposed algorithm provides a high performance by steering main beams to the directions of a desired signal, whereas steering nulls to the directions of the interference, using the estimated directions. The beamforming outputs obtained by steering the main beams to the distinct directions of resolvable multipath signals are combined in a maximal ratio manner to exploit angular diversity gain. The performance elf the proposed algorithm is finally evaluated in cellular mobile environments to verify its efficiency and is compared with that of least-squares beamforming algorithm, by taking the WiBro system as a target system.

키워드

참고문헌

  1. TTA, Specifications for 2.3GHz band portable internet service-Physical layer, 2005
  2. ETSI EN 300 744, Document A012 Rev.2, DVB: Framing structure, channel coding and modulation for digital terrestrial television, DVB. 2001
  3. M. Chryssomallis, 'Smart antennas,' IEEE Ant.and Propaga. Magazine, vol. 42, no. 3, pp. 129-136, 2002
  4. A. Kuchar, M. Tangemann, and E. Bonek, 'A real-time DOA-based smart antenna processor,' IEEE Trans. Veh. Techn., vol. 51, no. 6, pp. 1279-1293, 2002 https://doi.org/10.1109/TVT.2002.801737
  5. C. V. Rensburg and B. Friedlander, 'Performance of antenna arrays in an urban multi-path environments,' Proc. Globecom, pp. 157-161, 2000
  6. A. T. Alastalo and M. Kahola, 'Smart-antenna operation for indoor wireless local-area networks using OFMD,' IEEE Trans. Wireless Commun., vol. 2, no. 2, pp. 392-399, 2003 https://doi.org/10.1109/TWC.2003.809451
  7. F. W. Book and K. L. Baum, 'Adaptive antennas for OFDM,' Proc. VTC98, pp. 606-610, 1998
  8. R. B. Ertel, P. Cardieri, K. W. Sowerby, T. S. Rappaport, and J. H. Reed, 'Overview of spatial channel models for antenna array communication systems,' IEEE Personal Communications, pp. 10-22, Feb. 1998
  9. T. D. Pham, 'Statistical behavior and performance of adaptive antennas in multipath environments,' IEEE Trans. Microwave Theory and Techn., vol. 47, no. 6, pp. 727-731, 1999 https://doi.org/10.1109/22.769343
  10. K. I. Pedersen, P. E. Mogensen, and B. H. Fleury, 'Power azimuth spectrum in outdoor environments,' vol. 33, no. 18, pp. 1583-1584, Aug. 1997 https://doi.org/10.1049/el:19971029
  11. R. T. Williams, S. Prasad, A. K. Mahalanabis, and L. H. Sibul, 'An improved spatial smoothing technique for bearing estimation in multipath environment,' IEEE Trans. Acoust., Speech, and Sig. Proc., vol. 36, no. 4, pp. 425-432, Apr. 1988 https://doi.org/10.1109/29.1546
  12. R. O. Schmidt, 'Multiple emitter location and signal parameter estimation,' IEEE Trans. Ant.and Propa., vol. AP-34, no. 3, pp. 276-280, 1986
  13. A. Paulraj, R. Roy, and T. Kailath, 'Estimation of signal parameters via rotational invariance techniques,' IEEE Trans. Sig. Proc., vol. 37, no. 1, pp. 83-89, 1989
  14. B. D. Rao, K. V. S. Hari, ' Performance analysis of Root-MUSIC,' IEEE Trans. Acoust., Speech, and Sig. Proc., vol. 37, no. 12, pp. 1939-1949, Dec. 1989 https://doi.org/10.1109/29.45540