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

  • 제30권5A
  • /
  • Pages.436-444
  • /
  • 2005
  • /
  • 1226-4717(pISSN)
  • /
  • 2287-3880(eISSN)
한국통신학회 (The Korean Institute of Commucations and Information Sciences)
권호 표지

UMM(Unitary Matrix Modulation)을 이용한 LDPC(Low Density Parity Check) 코디드 OFDM 시스템

Low Density Parity Check (LDPC) Coded OFDM System Using Unitary Matrix Modulation (UMM)

  • 김남수 (모빌링크 텔레콤(주)) ;
  • 강환만 (삼성전자 정보통신총괄 통신연구소) ;
  • 조성호 (한양대학교 정보통신대학)
  • 발행 : 2005.05.01
PDF 다운로드
⟨ 이전 논문 다음 논문 ⟩

초록

다중 안테나 시스템에서 UMM (unitary matrix modulation)을 사용한 방법을 USTM (unitary space-time modulation)이라 부른다. OFDM 시스템에서 coherence bandwidth 만큼의 이격을 두고 UMM의 대각 행렬을 이용한 방법이 제안되고 있다. 또한 최근에 디코딩 방법이 간단하고 좋은 성능을 갖는 LDPC (low density parity check) 코드에 대한 연구가 진행되고 있다. 본 논문에서 UMM (unitary matrix modulation)을 사용하고 LDPC 코디드 된 OFDM 시스템을 제안한다. 또한 다중 송신 안테나를 사용하여 송신 diversity 이득을 얻는 것이 아니라, 하나의 송신 안테나를 이용하여 채널의 coherence bandwidth 만큼의 주파수 간격 (splitting)을 두어 채널에 대한 주파수 이득을 고려하여 UMM/OFDM 시스템을 설계 하였다. 이 방법을 이용하여 본 논문에서 제안된 UMM-S/OFDM에 대한 성능 특성을 다중 경로 Rayleigh 페이딩 채널 환경에서 시뮬레이션을 통하여 검증하였다.

Unitary matrix modulation (UMM) is investigated in multiple antennas system that is called unitary space-time modulation (USTM). In an OFDM, the diagonal components of UMM with splitting over the coherence bandwidth (UMM-S/OFDM) have been proposed. Recently LDPC code is strongly attended and studied due to simple decoding property with good error correction property. In this paper, we propose LDPC coded UMM-S/OFDM for increasing the system performance. Our proposed system can obtain frequency diversity using UMM-S/OFDM like USTM/OFDM, and large coding gain using LDPC code. The superior characteristics of the proposed UMM-S/OFDM are demonstrated by extensive computer simulations in multi-path Rayleigh fading channel.

키워드

참고문헌

  1. L. Cimini, 'Analysis and simulation of a digital mobile channel using OFDM,' IEEE Trans. on Commun., vol.33, pp.665-675, July 1985 https://doi.org/10.1109/TCOM.1985.1096357
  2. J.A. C. Bingham, 'Multicarrier modulation for data transmission: an idea whose time has come,' IEEE Commun. Mag., vol.28, pp.5-14, May, 1990 https://doi.org/10.1109/35.54342
  3. V. Tarokh, N. Seshadri, and A.R. Calderbank, 'Space-time codes for high data rate wireless communication: performance criterion and code construction,' IEEE Trans. on Information Theory, vol.44, no.2, pp.744-765, Feb., 1998 https://doi.org/10.1109/18.661517
  4. V. Tarokh, N. Seshadri, and A.R. Calderbank, 'Space-time block coding for wireless communication: performance results,' IEEE J. of Select. Areas Commun., vol.17, no.3, pp.451-460, Mar., 1999 https://doi.org/10.1109/49.753730
  5. V. Tarokh, A Naguib, N. Seshadri, and AR. Calderbank, 'Combined array processing and space-time coding,' IEEE Trans. on Information Theory, vol.45, no.2, pp.1121-1128, Feb., 1999 https://doi.org/10.1109/18.761255
  6. G. Raleigh, and J. M. Cioffi, 'Spatio-temporal coding for wireless communication,' IEEE Trans. on Commun., vol.46, no.3, pp.357-366, Mar., 1998 https://doi.org/10.1109/26.662641
  7. S. Fukumoto, M. Sawahashi, and F. Adachi, 'Performance comparison of forward link transmit diversity techniques for W -COMA mobile radio,' Proc. of PIMRC'99, vol.3, pp.1139-1143, Sept., 1999
  8. S. M. Alamouti, 'A simple transmit diversity technique for wireless communications,' IEEE J. Sel. Areas Commun, vol.16, no.8, pp.1451-1458, Oct., 1998 https://doi.org/10.1109/49.730453
  9. T.L.Marzetta, and B.M. Hochwald, 'Capacity of a mobile multiple-antenna communication link in Rayleigh flat fading,' IEEE Trans. on Information Theory, vol.45, no.1, pp. 139-157, Jan., 1999 https://doi.org/10.1109/18.746779
  10. B.M. Hochwald, and T.L.Marzetta, 'Unitary space-time modulation for multi-antenna communications in Rayleigh flat fading,' IEEE Trans. on Information Theory, vol.46, no.2, pp.543-563, Mar., 2000 https://doi.org/10.1109/18.825818
  11. B.M. Hochwald, et.al., 'Systematic design of unitary space-time constellation,' IEEE Trans. on Information Theory, vol.46, no.6, pp.1962-1973, Sept., 2000 https://doi.org/10.1109/18.868472
  12. C. Ahn, and I. Sasase, 'Convolutional coded coherent and differential unitary space-time modulated OFDM with bit interleaving for multiple antennas system,' IEICE Technical Report, SST-47, pp.75-80, October, 2002
  13. C. Ahn, and I. Sasase, 'Convolutional coded coherent and differential unitary space-time modulated OFDM with bit interleaving for multiple antennas system,' proc. of ISA 2003, Malta, Sept., 2003
  14. S. Y. Chung, G. D. Forney, Jr., T. J. Richardson, and R.Urbanke, 'On the design of low-density parity-check codes within 0.0045dB of the Shannon Limit,' IEEE Commun. Lett., vol. 5, no. 2, pp. 58-60, Feb. 2001 https://doi.org/10.1109/4234.905935
  15. R.G. Gallager, 'Low Density Parity Check Codes' IRE Trans. Inform. Theory, vol. 8, pp. 21-28, 1962 https://doi.org/10.1109/TIT.1962.1057683