최소 복호 복잡도를 갖는 새로운 준직교 시중간블록부호 설계

Design of New Quasi-Orthogonal Space-Time Block Code with Minimum Decoding Complexity

  • 채창현 (전남대학교 전자컴퓨터공학부 광대역무선통신연구실) ;
  • 최대원 (전남대학교 전자컴퓨터공학부 광대역무선통신연구실) ;
  • 정태진 (전남대학교 전자컴퓨터공학부 광대역무선통신연구실)
  • 발행 : 2007.12.31

초록

본 논문은 4개의 송신 안테나를 사용 할 경우 임의의 QAM 변조 방식과 준정지 Rayleigh 페이딩 채널 환경에서 최대 다이버시티 이득을 획득하고 더불어 full-rate을 획득하는 새로운 QO-STBC(quasi-orthogonal space-time block code)를 제안한다. 특히 제안된 부호는 기존의 MDC-QO-STBC(minimum decoding complex QO-STBC)와 같이 준직교 특성을 만족하여 수신단에서 2개의 실수 심벌들로 구성된 4개의 그룹들에 대하여 각각 독립적인 ML(maximum likelihood) 복호가 가능하다는 장점을 갖는다. 전산 실험 결과 제안된 부호는 모든 변조 방식들에 대하여 MDC-QO-STBC와 동일한 비트 오율(BER) 성능을 보여준다. 하지만 제안된 부호는 모든 송신 안테나들에서 성상 회전 이전의 신호들에 비해 PAPR(peak-to-average power ratio) 값들이 증가하는 기존의 MDC-QO-STBC와 달리 오직 2개의 송신 안테나들에서만 PAPR의 증가가 발생하도록 수정 가능하며 따라서 실제 송신 시스템 구현 시 훨씬 큰 이점을 갖게 된다.

In this paper, we propose a new quasi-orthogonal space-time block code(QO-STBC) achieving full rate and full diversity for general QAM and quasi-static Rayleigh fading channels with four transmit antennas. This code possesses the quasi orthogonal property like the conventional minimum decoding complexity QO-STBC(MDC-QO-STBC), which allows independently a maximum likelihood(ML) decoding to only require joint detection of two real symbols. By computer simulation results, we show that the proposed code exhibits the identical BER performance with the existing MDC-QO-STBC. However, the proposed code has an advantage in the transceiver implementation since the original coding scheme may be modified so that increases of peak-to-average power ratio occur at only two transmit antennas, but the MDC-QO-STBC does at all of transmit antennas.

키워드

참고문헌

  1. V. Tarokh, N. Seshadri, and A. R. Calderbank, 'Space-Time Codes for High Data Rate Wireless Communication: Performance Criterion and Code Construction,' IEEE Trans. Inform. Theory, Vol.44, no.2, pp.744-765, Mar. 1998 https://doi.org/10.1109/18.661517
  2. V. Tarokh, H. Jafarkhani, and A. R. Calderbank, 'Space-Time Block Coding for Wireless Communication: Theory of Generalized Orthogonal Designs,' IEEE Trans. Inform. Theory, Vol.45, pp.1456-1467, July 1999 https://doi.org/10.1109/18.771146
  3. S. M. Alamouti, 'A Simple Transmit Diversity Technique for Wireless Communications,' IEEE J. Select. Areas Commun., Vol.16, no.8, pp.1451-1458, Oct. 1998 https://doi.org/10.1109/49.730453
  4. J. Boutros ans E. Viterbo, 'Signal Space Diversity: A Power and Bandwidth Efficient Diversity Technique for Rayleigh Fading Channel,' IEEE Trans. Inform. Theory, Vol.44, pp.1453-1467, July 1998 https://doi.org/10.1109/18.681321
  5. X. Giraud, E. Boutillon, and J. C. Belfore, 'Algebraic Tools to Build Modulation Schemes for Fading Channels,' IEEE Trans. Inform. Theory, Vol.43, pp.938-952, May 1997 https://doi.org/10.1109/18.568703
  6. Y. Xin, Z. Wang, and G. B. Giannakis, 'Space-Time Diversity Systems Based on Linear Constellation Precoding,' IEEE Tran. Wireless Commun. Vol.2 pp.294-309, Mar. 2003 https://doi.org/10.1109/TWC.2003.808970
  7. T. Jung and K. Cheun, 'Design of Concatenated Space-Time Block Codes Using Signal Space Diversity and The Alamouti Scheme,' IEEE Commun. Lett., Vol.7, pp.329-331, July 2003 https://doi.org/10.1109/LCOMM.2003.814707
  8. H. Jafarkhani, 'A Quasi-Orthogonal Space-Time Block Code,' IEEE Trans. Commun., Vol.49, pp.1-4, Jan. 2001 https://doi.org/10.1109/26.898239
  9. W. Su and X.-G. Xia, 'Signal Constellations for Quasi-Orthogonal Space-Time Block Codes With Full Diversity,' IEEE Trans. Inform. Theory, Vol.50, pp.2331-2347, Oct. 2004 https://doi.org/10.1109/TIT.2004.834740
  10. L. Xian and H. Liu, 'Rate-One Space-Time Block Codes With Full Diversity,' IEEE Trans. Commun., Vol.53, pp.1986-1990, Dec. 2005 https://doi.org/10.1109/TCOMM.2005.860081
  11. C. Yuen, Y. L. Guan, and T. T. Tjhung, 'Quasi-Orthogonal STBC With Minimum Decoding Complexity,' IEEE Trans. Wireless Commun., vol.4, pp.2089-2094, Sep. 2005 https://doi.org/10.1109/TWC.2005.853890
  12. C. Yuen, Y. L. Guan, and T. T. Tjhung, 'Quasi-Orthogonal STBC With Minimum Decoding Complexity: Further Results,' in Proc. Wireless Communications and Nwtworking Conf. (WCNC), pp.483-488, New Orleans, LA, 2005