Journal of the Institute of Electronics and Information Engineers (전자공학회논문지)

The Institute of Electronics and Information Engineers (대한전자공학회)
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Novel LTE based Channel Estimation Scheme for V2V Environment

LTE 기반 V2V 환경에서 새로운 채널 추정 기법

  • Chu, Myeonghun (NARO Space Center, Korea Aerospace Research Institute) ;
  • Moon, Sangmi (NARO Space Center, Korea Aerospace Research Institute) ;
  • Kwon, Soonho (NARO Space Center, Korea Aerospace Research Institute) ;
  • Lee, Jihye (NARO Space Center, Korea Aerospace Research Institute) ;
  • Bae, Sara (NARO Space Center, Korea Aerospace Research Institute) ;
  • Kim, Hanjong (School of Electrical, Electronics & Communication Engineering, Korea University of Technology and Education) ;
  • Kim, Cheolsung (School of Electronics & Computer Engineering Chonnam National University) ;
  • Kim, Daejin (School of Electronics & Computer Engineering Chonnam National University) ;
  • Hwang, Intae (School of Electronics & Computer Engineering Chonnam National University)
  • 추명훈 (한국항공우주연구원 나로우주센터) ;
  • 문상미 (한국항공우주연구원 나로우주센터) ;
  • 권순호 (한국항공우주연구원 나로우주센터) ;
  • 이지혜 (한국항공우주연구원 나로우주센터) ;
  • 배사라 (한국항공우주연구원 나로우주센터) ;
  • 김한종 (한국기술교육대학 정보기술공학부) ;
  • 김철성 (전남대학교 전자컴퓨터공학과) ;
  • 김대진 (전남대학교 전자컴퓨터공학과) ;
  • 황인태 (전남대학교 전자컴퓨터공학과)
  • Received : 2016.06.07
  • Accepted : 2017.02.18
  • Published : 2017.03.25
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Abstract

Recently, in 3rd Generation Partnership Project(3GPP), there is a study of the Long Term Evolution(LTE) based vehicle communication which has been actively conducted to provide a transport efficiency, telematics and infortainment. Because the vehicle communication is closely related to the safety, it requires a reliable communication. Because vehicle speed is very fast, unlike the movement of the user, radio channel is rapidly changed and generate a number of problems such as transmission quality degradation. Therefore, we have to continuously updates the channel estimates. There are five types of conventional channel estimation scheme. Least Square(LS) is obtained by pilot symbol which is known to transmitter and receiver. Decision Directed Channel Estimation(DDCE) scheme uses the data signal for channel estimation. Constructed Data Pilot(CDP) scheme uses the correlation characteristic between adjacent two data symbols. Spectral Temporal Averaging(STA) scheme uses the frequency-time domain average of the channel. Smoothing scheme reduces the peak error value of data decision. In this paper, we propose the novel channel estimation scheme in LTE based Vehicle-to-Vehicle(V2V) environment. In our Hybrid Reliable Channel Estimation(HRCE) scheme, DDCE and Smoothing schemes are combined and finally the Linear Minimum Mean Square Error(LMMSE) scheme is applied to minimize the channel estimation error. Therefore it is possible to detect the reliable data. In simulation results, overall performance can be improved in terms of Normalized Mean Square Error(NMSE) and Bit Error Rate(BER).

최근 3GPP에서는 급증하는 차량 사고에 대처하고, 교통 효율, 텔레매틱스와 인포테인먼트를 제공하기 위해 LTE(Long Term Evolution) 기반 차량 통신에 대한 연구가 활발히 진행되고 있다. 차량 통신은 안전과 밀접한 관련이 있기 때문에, 신뢰성 있는 통신을 필요로 한다. 하지만 차량의 속도는 매우 빠르기 때문에 기존 사용자의 이동성과는 달리 무선 채널이 시간에 따라 빠르게 변하게 되어 전송 품질 저하 등 많은 문제가 발생하게 된다. 본 논문에서는 LTE 기반 V2V(Vehicle-to-Vehicle) 환경에서 채널 추정 기법을 제안한다. 기존 기법인 LS(Least Square) 채널 추정은 송 수신단이 알고 있는 파일럿 심볼을 이용해 얻어지며, DDCE(Decision Directed Channel Estimation)는 데이터 심볼을 이용해 채널 추정을 하고, CDP(Constructed Data Pilot) 기법은 인접한 두 데이터 심볼 사이에서 상관이 큰 특성을 이용하며, 그리고 STA(Spectral Temporal Averaging) 기법은 주파수와 시간 영역에서 채널을 평균을 취한다. 또한 Smoothing 기법은 데이터 결정 오류에 의한 최대치를 줄여준다. 제안기법인 HRCE(Hybrid Reliable Channel Estimation)는 기존의 Smoothing 기법에 LMMSE(Linear Minimum Mean Square Error)를 적용함으로써 더 정확한 채널 추정이 이루어져 신뢰성 있는 데이터 검출을 가능하게 한다. 모의실험 결과, 제안한 기법이 NMSE(Normalized Mean Square Error)와 BER(Bit Error Rate) 측면에서 전체적으로 성능이 향상 된 것을 볼 수 있다.

Keywords

References

  1. YiShi, "LTE-V: A Cellular-Assisted V2X Communication Technology" in ITU Workshop, Beijing, China, July. 28-29th 2015.
  2. Jaemin Kwak, Pusik Park, Daekyo Shin, Kitaeg Lim, and Jongchan Choi, "Implementation of Embedded System for IEEE 802.11p based OFDM-DSRC Communications" in ISOCC Conference, Page: 431-434, Oct. 2006.
  3. Sangmi Moon, Myeonghun Chu, Hanjong Kim, Dajin Kim, Intae Hwang, "FFT-based Channel Estimation Scheme in LTE-A Downlink System" in IEIE, Vol. 53, NO.3, Page: 11-20, March. 2016.
  4. Jianjun Ran, Rainer Griinheid, Hermann Rohling, Edgar Bolinth, Ralf Kern, "Decision-directed Channel Estimation Method for OFDM systems with high velocities" in Vehicular Technology Conference, 2003. VTC 2003-Spring. The 57th IEEE Semiannual, Vol.04, Page: 2358-2361, 2003.
  5. Zijun Zhao, Xiang Cheng, Miaowen Wen, Bingli Jiao, Cheng-Xiang Wang, "Channel Estimation Schemes for IEEE 802.11p Standard" in IEEE Intelligent Transportation Systems Magazine, Vol 5, Page: 38-49, 2013. https://doi.org/10.1109/MITS.2013.2270032
  6. Joseph A. Fernandez, "Dynamic Channel Equalization for IEEE 802.11p Waveforms in the Vehicleto-Vehicle Channel" in Communication, Control, and Computing (Allerton), 2010 48th Annual Allerton Conference on, Page: 542-551, Oct. 2010.
  7. Andre Bourdoux, Hans Cappelle, Antoine Dejonghe, "Channel Tracking for Fast Time-Varying Channels in IEEE 802.11p Systems" in Global Telecommunications Conference (GLOBECOM 2011), 2011 IEEE, Page: 1-6, Dec. 2011.