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비면허대역 LTE를 위한 멀티캐리어 액세스 기법

Multi-Carrier Listen Before Talk Mechanism for LTE in Unlicensed Spectrum

  • Kim, Sanghyun (Seoul National University of Science and Technology, Department of Electrical and Information Engineering) ;
  • Vu, Long Hoang (Seoul National University of Science and Technology, Department of Electrical and Information Engineering) ;
  • Noh, Minseok (WILUS Inc.) ;
  • Kwak, Jinsam (WILUS Inc.) ;
  • Yun, Ji-Hoon (Seoul National University of Science and Technology, Department of Electrical and Information Engineering)
  • 투고 : 2016.05.01
  • 심사 : 2016.07.21
  • 발행 : 2016.07.31

초록

본 논문은 비면허대역을 위한 LTE 통신 기술인 LAA(Licensed Assisted Access)가 복수의 주파수 채널을 사용해 하향링크 전송을 수행하기 위한 액세스 기법을 설명하고, 액세스 기법의 세부 동작 설계에 따른 Wi-Fi와의 공존 특성 및 각 통신 기술의 성능 변화를 시뮬레이션을 통해 보인다. 이를 위해 LAA의 채널 본딩 규칙 적용 여부, LBT(Listen Before Talk)를 수행하는 채널, LBT 채널을 동적으로 변경 시 CW(Contention Window)의 설정방법, 그리고 Wi-Fi의 대역폭 설정 방식과 CW 조절 방식을 고려한다. 각 요소를 변경하였을 때 상호 간의 성능 변동 경향을 확인하고, 이를 통해 두 기술의 공존을 위해 다양한 요소가 복합적으로 고려되어야 함을 보인다.

An LTE enhancement for licensed-assisted access (LAA) to unlicensed spectrum has been studied recently and the first version of its design has been released in early 2016. As both 2.4 and 5GHz ISM bands have multiple channels and Wi-Fi devices already support multi-channel operation, LTE LAA has also been designed such that an eNB can access multiple channels at the same time. In this paper, we review several design variants of listen before talk (LBT) procedure for multi-channel transmission in downlink and perform simulation to investigate coexistence of Wi-Fi and LAA as well as the performance of both.

키워드

참고문헌

  1. 3GPP Technical Report, 36.889, Study on Licensed-Assisted Access to Unlicensed Spectrum, v1.0.0, 2015.
  2. 3GPP Technical Specification 36.213, E-UTRA Physical layer procedures, Rev. 13.1.1, Mar. 2016.
  3. Qualcomm, Multi-carrier LBT operation for LAA, 3GPP R1-152784, May 2015.
  4. A. M. Cavalcante, et al., "Performance evaluation of LTE and Wi-Fi coexistence in unlicensed bands," in Proc. IEEE Veh. Technol. Conf., pp. 1-6, Dresden, Germany, Jun. 2013.
  5. S. W. Lee, Y. Yang, and J. Jo, "A coexistence study between LTE-Advanced system and current mobile communication system," J. KICS, vol. 35, no. 10, pp. 1019-1025, Oct. 2010.
  6. S. H. Lim, M. Y. Jung, and S. W. Lee, "Adjacent channel coexistence of LTE in unlicensed spectrum," J. KICS, vol, 40, no. 10, pp. 1879-1888, Oct. 2015. https://doi.org/10.7840/kics.2015.40.10.1879
  7. L. H. Vu, M. Noh, J. Kwak, and J. H. Yun, "Multi-Carrier Listen Before Talk Mechanism for LTE in Unlicensed Spectrum," in Proc. KICS Winter Conference, pp. 388-389, Pyeongchang, Korea, January 2016.
  8. Broadcom, Discussion on LAA DL Multichannel LBT, 3GPP R1-155547, Oct. 2015.
  9. WILUS, Consideration on Multicarrier LBT for LAA, 3GPP RAN1 contribution, R1-157330, Nov. 2015.
  10. Ericsson, On Channel Access Solutions for LAA Multi-Carrier Transmission, R1-156033, Oct. 2015.