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

The Korean Institute of Commucations and Information Sciences (한국통신학회)
권호 표지
DOI QR코드

DOI QR Code

Network-Coded Bi-Directional Relaying Over an Asymmetric Channel

비대칭 채널에서의 네트워크 코딩 기반 양방향 릴레이 전송 기법

  • 류현석 (고려대학교 전기전자파공학과 무선정보시스템공학 연구실) ;
  • 이준석 (LG전자) ;
  • 강충구 (고려대학교 전기전자파공학과 무선정보시스템공학 연구실)
  • Received : 2012.12.31
  • Accepted : 2013.03.04
  • Published : 2013.03.29
Download PDF
⟨ Previous Next ⟩

Abstract

In this paper, we consider network-coded bi-directional relaying (NCBR) schemes over an asymmetric channel, in which bi-directional links have the different channel quality, as well as the asymmetric traffic load. In order to deal with asymmetric nature, two different types of NCBR schemes are considered: network coding after padding (NaP) and network coding after fragmentation (NaF). Even if NaP has been known as only a useful means of dealing with the asymmetry in traffic load up to now, our analysis shows that its gain can be significantly lost by the asymmetry in channel quality, under the given bit error performance constraint. Furthermore, it is shown that NaF always outperforms NaP, as well as traditional bi-directional relaying scheme.

본 논문에서는 양방향 링크의 채널 상태와 트래픽 부하가 비대칭적인 채널에서 네트워크 코딩을 적용하는 기법과 그 방식에 따른 성능에 대해서 살펴본다. 이러한 양방향 링크의 비대칭성을 반영하기 위해 패딩후 네트워크 코딩(Network Coding after Padding: NaP) 방식과 분할 후 네트워크 코딩(Network Coding after Fragmentation: NaF) 방식을 고려한다. NaP 방식은 지금까지 트래픽 부하의 비대칭성만을 반영하기 위해 고려된 바 있으며, 본 논문에서는 실제로 채널의 상태를 동시에 고려할 경우에는 NaP 방식이 갖는 기존의 이득이 오히려 열화되는 것을 보인다. 또한, NaF 방식이 일반적인 양방향 링크 기법뿐만 아니라 NaP 방식보다 항상 성능이 좋다는 것을 보인다.

Keywords

References

  1. R. Ahlswede, N. Cai, S.Y.R. Li, and R.W. Yeung, "Network information flow," IEEE Trans. Inform. Theory, vol.46, no.4, pp. 1204-1216, July 2000. https://doi.org/10.1109/18.850663
  2. S. Y. R. Li, R. W. Yeung, and N. Cai, "Linear network coding," IEEE Trans. Inform. Theory, vol. 49, no. 2, pp. 371-381, Feb. 2003. https://doi.org/10.1109/TIT.2002.807285
  3. R. Koetter and M. Medard, "An algebraic approach to network coding," IEEE/ACM Trans. Networking, vol. 11, no. 5, pp. 782-795, Oct. 2003. https://doi.org/10.1109/TNET.2003.818197
  4. S. Katti, H. Rahul, W. Hu, R. Hariharan, M. Medard, and J. Crowcroft, "Xors in the air: practical wireless network coding," IEEE/ACM Trans. Networking, vol.16, no.3, pp. 497-510, June 2008. https://doi.org/10.1109/TNET.2008.923722
  5. P. Larsson, N. Johansson, and K. E. Sunell, "Coded bi-directional relaying," in proc. IEEE VTC 2006, pp. 851-855, Montreal, Canada, May 2006.
  6. M. Feng, X. She, and L. Chen, "Enhanced bidirectional relaying schemes for multi-hop communications," in Proc. GLOBECOM 2008, pp. 1-6, New Orleans, U.S.A., Nov. 2008.
  7. J. Hou, C. Hausl, and R. Koetter, "Distributed turbo coding schemes for asymmetric two-way relay communication," in Proc. Inter. Symp. Turbo Codes Related Topics (ISTC) 2008, pp. 237-242, Lausanne, Switzerland, Sep. 2008.
  8. C. Hausl, O. Iscan, and F. Rossetto, "Optimal time and rate allocation for a network-coded bi-directional two-hop communication," in Proc. European Wireless Conf. (EW) 2010, pp. 1015-1022, La Thuile, Italy, Apr. 2010.
  9. J. Zhao, A. W. M. Kuhn, and G. Bauch, "Asymmetric data rate transmission in two-way relaying systems with network coding," in Proc. IEEE Inter. Commun. Conf. (ICC) 2010, pp. 1-6, Cape Town, South Africa, May 2010.
  10. A. J. Goldsmith and S. G. Chua, "Variable-rate variable-power M-QAM for fading channels," IEEE Trans. Commun., vol.45, no.10, pp. 1218-1230, Oct. 1997. https://doi.org/10.1109/26.634685
  11. A. J. Goldsmith and S. G. Chua, "Adaptive coded modulation for fading channels," IEEE Trans. Commun., vol.46, no.5, pp. 595-602, May 1998. https://doi.org/10.1109/26.668727
  12. A.J. Goldsmith, Wireless Communications, Cambridge University Press, 2005.
  13. J.-S. Lee, H.-S. Ryu, and C. G. Kang, "Network coding for turbo-coded system in asymmetric two-way relay," in Proc. KICS Summer 2010, pp. 1-2, Jeju Island, Korea, June 2010.