Journal of the Institute of Electronics Engineers of Korea TC (대한전자공학회논문지TC)

The Institute of Electronics and Information Engineers (대한전자공학회)
권호 표지

A Downlink Spectral Efficiency Improvement Scheme Using Intercell Cooperative Spatial Multiplexing and Beamforming

셀 간 협조적 공간 다중화 및 빔포밍을 이용한 하향링크 전송 효율 증대 방안

  • Chang, Jae-Won (Department of Electronics Engineering, Sogang University) ;
  • Jin, Gwy-Un (Department of Electronics Engineering, Sogang University) ;
  • Sung, Won-Jin (Department of Electronics Engineering, Sogang University)
  • Published : 2008.07.25
Download PDF
⟨ Previous Next ⟩

Abstract

In typical cellular systems using frequency reuse scheme, the terminal suffers a performance degradation due to the intercell interference signals from adjacent cells as the terminal moves toward the cell boundary. In this paper, a signal transmission and reception scheme which achieve spatial multiplexing and beamforming gain from a distributed MIMO (multiple-input multiple-output) channel using multiple-antenna terminal is proposed for the spectral efficiency enhancement in a multi-cell downlink environment, when geographically separated base stations cooperatively transmit signals. In particular, we analyze the effective signal-to-interference ratio and spectral efficiency of the proposed scheme for different frequency reuse patterns and for varying numbers of receive antennas, and compare with the performance of the MRC (maximal ratio combining) reception scheme in typical cellular systems. We evaluate the amount of transmission efficiency of the scheme by comparing the performance near the cell boundary where the strong intercell interference is experienced.

주파수 재사용 기법을 사용하는 셀룰러 시스템의 경우 단말기가 셀 경계로 이동할수록 인접 셀로부터 오는 간섭 신호의 영향을 받게 되어 성능 열화를 겪게 된다. 본 논문에서는 다중 셀 시스템의 하향링크 전송 시, 지리적으로 떨어져 있는 다수의 기지국에서 상호 협력을 통해 다중 안테나 단말기에 협조적으로 신호를 전송하는 경우 기지국들과 단말기간에 형성된 분산 MIMO (multiple-input multiple-output) 채널을 이용하여 공간 다중화 및 빔포밍 이득을 얻을 수 있는 전송 방안 및 수신 기법을 제안한다. 특히, 주파수 재 사용률과 단말기의 수신안테나 개수의 변화에 따라 제안 기법의 유효 신호 대 간섭 비와 전송효율을 분석 및 산출하고, 기존 셀룰러 시스템에서 널리 사용되는 MRC (maxim ratio combining) 수신 기법의 성능과 비교한다. 셀 경계에서의 성능 이득을 비교함으로써 인접 셀 간섭이 큰 영역에서 제안 기법을 사용할 때 단말기의 전송 효율 향상정도를 평가한다.

Keywords

References

  1. J. N. Laneman, D. N. C. Tse, and G. W. Wornell, "Cooperative diversity in wireless networks: efficient protocols and outage behavior," IEEE Trans. Inform. Theory, vol. 50, no. 12, pp. 3062-3080, Dec. 2004 https://doi.org/10.1109/TIT.2004.838089
  2. A. A. M. Saleh, A. J. Rustako, and R. S. Roman, "Distributed antennas for indoor radio communications," IEEE Trans. Commun., vol. 35, pp. 1245-1251, Dec. 1987 https://doi.org/10.1109/TCOM.1987.1096716
  3. Z. Wang and R. A. Stirling-Gallacher, "Frequency reuse scheme for cellular OFDM systems," Electronics Letters, vol. 38, no. 8, pp. 387-388, Apr. 2002 https://doi.org/10.1049/el:20020255
  4. L. Haipeng, Z. Lei, Z. Xin, and Y. Dacheng, "A novel multi-cell OFDMA systems structure using fractional frequency reuse," in Proc. IEEE PIMRC'07, pp. 1-5, Sept. 2007
  5. B. D. Rao and Y. Ming, "Performance of maximal ratio transmission with two receive antennas," IEEE Trans. Commun., vol. 51, pp. 894-895, June 2003 https://doi.org/10.1109/TCOMM.2003.813181
  6. A. Maref and S. Aissa, "Closed-form expressions for the outage and ergodic Shannon capacity of MIMO MRC systems," IEEE Trans. Commun., vol. 53, pp. 1092-1095, July 2005 https://doi.org/10.1109/TCOMM.2005.851564
  7. A. Shah and A. M. Haimovich, "Performance analysis of maximal ratio combining and comparison with optimum combining for mobile radio communications with cochannel interference," IEEE Trans. Veh. Technol., vol. 49, no. 4, pp. 1454-1463, July 2000 https://doi.org/10.1109/25.875282
  8. J. Proakis, Digital Communications, 4/e. New york: McGraw-Hill, 2001
  9. A. J. Paulraj, D. A. Gore, R. U. Nabar, and H. Bolcskei, "An overview of MIMO communications—A key to gigabit wireless," Proc. IEEE, vol. 92, no. 2, pp. 198-218, Feb. 2004 https://doi.org/10.1109/JPROC.2003.821915
  10. P. W. Wolniansky, G. J. Foschini, G. D. Golden, and R. A. Valenzuela, "V-BLAST: An architecture for realizing very high data rates over the rich-scattering wireless channel," in Proc. IEEE ISSSE'98, pp. 295-300. Sept. 1998
  11. S. Catreux, P. F. Driessen, and L. J. Greenstein, "Data throughputs using multiple-input multiple-output (MIMO) techniques in a noise-limited cellular environment," IEEE Trans. Wireless Commun., vol. 1, pp. 226-235, Apr. 2002 https://doi.org/10.1109/7693.994816
  12. Y. Tokgoz and B. D Rao, "Performance analysis of maximum ratio transmission based multi-cellular MIMO systems," IEEE Trans. Wireless Commun., vol. 5, no. 1, pp. 83-89, Jan. 2006 https://doi.org/10.1109/TWC.2006.1576532
  13. J. B. Andersen, "Array gain capacity for known random channel with multiple element arrays at both ends," IEEE J. Select. Areas Commun., vol. 18, pp. 2172-2178, Nov. 2000 https://doi.org/10.1109/49.895022