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

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

셀룰러 OFDMA 시스템을 위한 간섭의 집중화

Interference Localization for Cellular OFDMA Systems

  • 임민중 (동국대학교 정보통신공학과)
  • Rim, Min-Joong (Department of Information and Communication Engineering, Dongguk University)
  • 발행 : 2007.03.25
PDF 다운로드
⟨ 이전 논문 다음 논문 ⟩

초록

셀룰러 OFDMA 시스템에서는 인접 셀 간섭이 각 부반송파별로 다른 값을 가진다. 만일 각 부반송파의 간섭의 양의 추정이 가능하다면 채널 복호기에 입력되는 데이터의 크기를 간섭의 양에 반비례하도록 조절함으로써 성능을 향상시킬 수 있다. 전통적인 셀룰러 시스템들이 셀간 간섭의 영향을 완화시키기 위하여 간섭의 평균화 기술을 선호하는데 반해서 본 논문에서는 셀간 간섭 추정이 가능하다고 가정할 때 적은 수의 부반송파에 간섭을 집중시킴으로써 시스템 성능을 크게 향상시킬 수 있음을 보인다. 셀간 간섭의 추정이 이루어지지 않는 경우, 특정 부반송파에 큰 간섭이 오지 않도록 간섭을 평균화하는 것이 유리한 반면, 셀간 간섭의 추정이 가능한 경우에는 간섭의 평균화를 사용하는 것보다 간섭의 집중화를 사용하는 것이 더 이득을 얻을 수 있다.

Cellular OFDMA systems may suffer from various amounts of inter-cell interferences according to subcarriers. If it is possible to estimate the interference level of each subcarrier, the performance can be improved by adjusting the magnitude of channel decoder input signals inversely proportional to the interference amounts. While conventional cellular systems prefer to use interference averaging techniques for mitigating inter-cell interferences, this paper shows that localizing inter-cell interferences to the reduced number of subcarriers can significantly improve the system performance assuming thatinterference estimation can be employed. If interference estimation is not used, it is more favorable to use interference averaging techniques to avoid excessive interference levels to certain subcarriers. On the other hand, if interference estimation can be employed, interference localization is more beneficial than interference averaging.

키워드

참고문헌

  1. Z. Wang, and G. B. Giannakis, 'Wireless Multicarrier Communications,' IEEE Signal Processing Magazine, Vol.17, No.3, pp.29-48, May 2000 https://doi.org/10.1109/79.841722
  2. X. Pengfei, Z. Shengli, and G.B. Giannakis, 'Bandwidth and Power-efficient Multicarrier Multiple Access,' IEEE Transactions on Communications, Vol.51, No.11, pp.1828-1837, November 2003 https://doi.org/10.1109/TCOMM.2003.819198
  3. IEEE P802.16e/D12: Part 16: Air Interface for Fixed and Mobile Broadband Wireless Access Systems: Amendment for Physical and Medium Access Control Layers for Combined Fixed and Mobile Operation in Licensed Bands, October 2005
  4. IEEE802.20: QFDD and QTDD: Proposed Draft Air Interface Specification, Qualcomm, October 2005
  5. S. Tsumura, R. Mino, S. Hara, and Y. Hara, 'Performance Comparison of OFDM-FH and MC-CDM in Single and Multi-Cell Environments,' VTC 2005-Spring, Vol.3, pp.1730-1734, June 2005
  6. S. Hara and R. Prasad, 'Overview of Multicarrier CDMA,' IEEE Communications Magazine, Vol.35, No.12, pp.126-133, December 1997
  7. 임민중, '셀룰러 OFDMA 상향링크 시스템의 셀간 간섭추정 알고리즘,' 전자공학회논문지, 제43권 TC편 제10호, pp.55-59, October 2006
  8. A. Paulraj, R. Nabar, and D. Gore, Introduction to Space-Time Wireless Communications, Cambridge University Press 2003
  9. R1-050047, Alcatel, 'Interference Coordination in New OFDM DL Air Interface,' 3GPP RAN WG1 #41, Athens, Greece, May 2005
  10. R1-050808, ETRI, 'Inter-cell Interference Management in Practical Environments,' 3GPP RAN WG1 #42, London, UK, August 2005
  11. R1-050896, Qualcomm, 'Description and simulations of interference management technique for OFDMA based E-UTRA downlink evaluation,' 3GPP RAN WG1 #42, London, UK, September 2005