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

The Institute of Electronics and Information Engineers (대한전자공학회)
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Performance Analysis of New LMMSE Channel Interpolation Scheme Based on the LTE Sidelink System in V2V Environments

V2V 환경에서 LTE 기반 사이드링크 시스템의 새로운 LMMSE 채널 보간 기법에 대한 성능 분석

  • Chu, Myeonghun (School of Electronics & Computer Engineering Chonnam National University) ;
  • Moon, Sangmi (School of Electronics & Computer Engineering Chonnam National University) ;
  • Kwon, Soonho (School of Electrical, Electronics & Communication Engineering, Korea University of Technology and Education) ;
  • Lee, Jihye (School of Electronics & Computer Engineering Chonnam National University) ;
  • Bae, Sara (School of Electronics & Computer Engineering Chonnam National University) ;
  • 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 (전남대학교 전자컴퓨터공학과) ;
  • 문상미 (전남대학교 전자컴퓨터공학과) ;
  • 권순호 (한국기술교육대학 정보기술공학부) ;
  • 이지혜 (전남대학교 전자컴퓨터공학과) ;
  • 배사라 (전남대학교 전자컴퓨터공학과) ;
  • 김한종 (한국기술교육대학 정보기술공학부) ;
  • 김철성 (전남대학교 전자컴퓨터공학과) ;
  • 김대진 (전남대학교 전자컴퓨터공학과) ;
  • 황인태 (전남대학교 전자컴퓨터공학과)
  • Received : 2016.07.02
  • Accepted : 2016.09.28
  • Published : 2016.10.25
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Abstract

To support the telematics and infotainment services, vehicle-to-everything (V2X) communication requires a robust and reliable network. To do this, the 3rd Generation Partnership Project (3GPP) has recently developed V2X communication. For reliable communication, accurate channel estimation should be done. However, because vehicle speed is very fast, radio channel is rapidly changed with time. Therefore, it is difficult to accurately estimate the channel. In this paper, we propose the new linear minimum mean square error (LMMSE) channel interpolation scheme based on the Long Term Evolution (LTE) sidelink system in vehicle-to-vehicle (V2V) environments. In our proposed reduced decision error (RDE) channel estimation scheme, LMMSE channel estimation is applied in the pilot symbol, and then in the data symbol, smoothing and LMMSE channel interpolation scheme is applied. After that, time and frequency domain averaging are applied to obtain the whole channel frequency response. In addition, the LMMSE equalizer of the receiver side can reduce the error propagation due to the decision error. Therefore, it is possible to detect the reliable data. Analysis and simulation results demonstrate that the proposed scheme outperforms currently conventional schemes in normalized mean square error (NMSE) and bit error rate (BER).

V2X(Vehicle-to-Everything) 통신은 다양한 텔레매틱스(telematics)와 인포테인먼트(infotainment) 서비스를 제공하기 위해 신뢰성이 있으며 견고한 네트워크가 요구된다. 이를 위해, 현재 3GPP(3rd Generation Partnership Project)에서는 V2X 통신에 대한 표준화를 진행하고 있다. 신뢰성 있는 통신을 위해서는, 정확한 채널 추정이 우선적으로 이루어져야 한다. 그러나 차량은 속도가 매우 빠르기 때문에 시간에 따라 무선 채널이 빠르게 변하므로 채널을 정확히 추정하기 힘들다. 본 논문에서는 V2V(Vehicle-to-Vehicle) 환경에서 LTE(Long Term Evolution) 기반 사이드링크 시스템의 새로운 LMMSE(Linear Minimum Mean Square Error) 채널 보간 기법을 제안한다. 제안한 기법인 RDE(Reduced Decision Error)는 파일럿 심볼에서 LMMSE를 이용하여 채널 추정을 하고, 데이터 심볼에서 Smoothing 후 LMMSE 채널 보간 기법을 적용한다. 이후 시간영역과 주파수영역에서 평균을 취하여 전체 채널 주파수 응답을 얻어낼 수 있다. 이때, 수신단의 등화기로 LMMSE를 이용하여 결정 오차에 의한 오차 전파를 줄일 수 있다. 그러므로, 신뢰성 있는 데이터 검출이 가능하다. 모의실험 결과, 제안한 기법이 NMSE(Normalized Mean Square Error)와 BER(Bit Error Rate) 측면에서 기존 기법보다 전체적으로 성능이 향상된 것을 볼 수 있다.

Keywords

References

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