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

The Korean Institute of Commucations and Information Sciences (한국통신학회)
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Femtocell Searching Technique Using Synchronization Signals for Next-Generation Mobile Communication Systems

차세대 이동통신 시스템에서 동기신호를 이용한 펨토셀 탐색 기법

  • Received : 2012.09.14
  • Accepted : 2013.01.04
  • Published : 2013.01.31
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Abstract

In this paper, we propose a femtocell searching technique which can prevent a macrocell UE(user equipment) from losing synchronism to its serving macrocell near closed access femtocells in co-channel deployment due to the leakage of femtocell signals by using a CS(Common Signal). The CS, commonly transmitted by femtocells in a macrocell at the same time, enables the macrocell UEs to be kept synchronized with their serving macrocells since the CINR(Carrier to Interference and Noise Ratio) of base stations in macrocell can be kept high even near closed access femtocells. Also, the CS is designed in such a way that a macrocell UE can recognize the existence of femtocell by using the metric CSCINR(Common Signal Carrier to Interference and Ratio) measured with CS. In addition, the proposed femtocell searching technique can reduce the frequency of femtocell searching trial by using the metric on mobility of a macrocell UE defined in this paper, and the reduction of the frequency of handover trial can be also expected as a byproduct.

본 논문에서는 co-channel deployment 방식을 사용하는 closed access 펨토셀 주변에서 마크로셀 단말의 동기소실 문제를 해결하고 펨토셀의 전력 누수 때문에 발생하는 셀 탐색을 줄이기 위하여 CS(Common Signal)을 사용한 펨토셀 탐색 기법을 제안한다. CS는 특정 마크로셀 내의 펨토셀들이 같은 시간에 공통으로 전송하는 신호로, 펨토셀이 CS를 송신할 경우 마크로셀 내에서 마크로셀 기지국의 CINR(Carrier to Interference Noise and Ratio) 값이 크게 유지되어 closed access 펨토셀 주변에서 마크로셀 단말이 동기를 유지할 수 있다. 또한, CS는 단말이 CS를 사용하여 측정한 CSCINR(Common Signal Carrier to Interference Noise and Ratio) 값을 이용하여 펨토셀 존재 여부를 판단할 수 있도록 설계되므로, 마크로셀 단말은 마크로셀 기지국에 동기를 유지하면서 펨토셀 존재여부를 판단할 수 있다. 그리고 제안된 방식에서는 옥외에서 이동 중인 단말이 자신의 이동성을 이용하여 펨토셀 탐색 여부를 판단함으로써 단말의 펨토셀 탐색 빈도를 줄인다. 따라서 펨토셀 탐색에 대한 부담을 줄이고, 이에 대한 부가적 이득으로 핸드오버 시도의 빈도 감소를 기대할 수 있다.

Keywords

References

  1. A. Golaup, M. Mustapha, and L.B. Patanapongpibul, "Femtocell access control strategy in UMTS and LTE," IEEE Commun. Mag., vol. 47, no. 9, pp.117-123, Sep. 2009.
  2. R. Y. Kim, J.S. Kwak, and K. Etemad, "WiMAX femtocell: requirements challenges, and solutions," IEEE Commun. Mag., vol. 47, no. 9, pp.84-91, Sep. 2009.
  3. G. Roche, A. Valcarce, D. Lopez-Perez, and J. Zhang, "Access control mechanisms for femtocells," IEEE Commun. Mag., vol. 48, no. 1, pp.33-39, Jan. 2010. https://doi.org/10.1109/MCOM.2010.5394027
  4. Y. Li, A. Maeder, L. Fan, A. Nigam, and J. Chou, "Overview of femtocell support in advanced WiMAX systems," IEEE Commun. Mag., vol. 49, no. 7, pp. 122-130, Jul. 2011.
  5. J.I. Choi, J.K. Nam, W.K. Seo, Y.Z. Cho, "An Efficient Femto-cell Scanning Scheme Using Network Assistance in IEEE 802.16e System," J. KICS, vol. 36, no. 1, pp. 21-28, Jan. 2011. https://doi.org/10.7840/KICS.2011.36B.1.21
  6. S. G. Niri, and R. Tafazolli, "Position assisted handover algorithm for multi layer cell architecture," in proc. IEEE VTC 1999, pp. 569-572, Sep. 1999.
  7. K.L. Yeung, and S. Nanda, "Channel management in microcell/macrocell cellular radio systems," IEEE Trans. Veh. Technol., vol. 45, no. 4, pp. 601-612, Nov. 1996. https://doi.org/10.1109/25.543716
  8. S.A. Ghorashi, L. Wang, F. Said, and A.H. Aghvami, "Impact of macrocell-hotspot handover on cross-layer interference in multi-layer W-CDMA networks," in proc. 5th European Pers. Mobile Commun. Conf., pp. 580-584, Apr. 2003.
  9. O.B. Karimi, J. Liu, and C. Wang, "Seamless wireless connectivity for multimedia services in high speed trains," IEEE J. Sel. Area. Commun., vol. 30, no. 4, pp. 729-939, May 2009.
  10. S.K. Bahl, "Cell searching in WCDMA," IEEE Potentials, vol. 22, no. 2, pp. 16-19, Apr. 2003.
  11. H.D. Bae, and N.H. Park, "Impact of reading system information in inbound handover to LTE femtocell," in proc. APCC 2010, pp. 476-480, 2010
  12. C. Bontu, and E. Illidge, "DRX mechanism for power saving in LTE," IEEE Commun. Mag., vol. 47, no. 6, pp. 48-55, Jun. 2009.
  13. S. Huan, K. Linling, and L. Jianhua, "Interference avoidance in OFDMA-based femtocell network," in proc. IEEE YC-ICT 2009, pp. 126-129, Dec. 2009.
  14. R.Y. Kim, Y.Y. Kim, A.A. Yazdi, S. Sorour, and S. Valaee, "Joint reduction of peak-to-average power ratio, cubic metric, and block error rate in OFDM systems using network coding," IEEE Trans. Veh. Technol., vol. 60, no. 9, pp. 4363-4373, Nov. 2011. https://doi.org/10.1109/TVT.2011.2172698
  15. H.J. Zepernick, and A. Finger Pseudo Random Signal Processing, John Wiley & Sons, Ltd., Chichester, UK, 2005
  16. H.S. Ju, S.W. Lee, D.S. Hong, K.Y. Han, and J.H. Jeon, "Non-handover based mobility management in hierarchically structured cellular networks," in proc. Comp. Netw. and Services Research Conf. 2010, pp. 369-375, May 2010.
  17. Y.U. Chung, D.J. Lee, D.H. Cho, and B.C. Shin, "Macrocell/Microcell selection schemes based on a new velocity estimation in multitier cellular system," IEEE Trans. Veh. Technol., vol. 51, no. 5, pp. 893-903, Sep. 2002. https://doi.org/10.1109/TVT.2002.801764
  18. A.G. Zajic, "Estimation of mobile velocities and direction of movement in mobile-to-mobile wireless fading channels," IEEE Trans. Veh. Technol., vol. 61, no. 1, Jan. 2012.
  19. K.E. Baddour, and N.C. Beaulieu, "Robust doppler spread estimation in nonisotropic fading channels," IEEE Trans. Wirel. Commun., vol. 4, no. 6, pp. 2677-2682, Nov. 2005. https://doi.org/10.1109/TWC.2005.858362
  20. W.C. Jakes, Microwave Mobile Communications, John Wiley & Sons, Inc., New York, 1974
  21. Alcatel-Lucent, picoChip Designes, Vodafone "Simulation Assumptions and Parameters for FDD HeNB RF Requirements," 3GPP Tech. Doc., Tdoc R4-092042, 3GPP TSG RAN WG4 Meeting #51bis, San Francisco, USA, May 2007.
  22. Recommendation (1997) ITU-R M.1225. Guidelines for Evaluation of Radio Transmission Technologies for IMT-2000.
  23. I. G. Kim, Y. Han, and H. Chung, "An efficient synchronization signal structure for OFDM-based cellular systems," IEEE Trans. Wirel. Commun., vol. 9, no. 1, pp. 99-105, Sep. 2010. https://doi.org/10.1109/TWC.2010.01.090516