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Fading Effects and Antenna Diversity Tests of WAVE Communications

WAVE 통신의 페이딩 효과와 안테나 다이버시티 실험

  • Choi, Hyun-Kyun (ETRI Industries IT Convergence Research Department) ;
  • Oh, Hyun-Seo (ETRI Industries IT Convergence Research Department) ;
  • Cho, Woong (Jungwon University, Department of Computer System Engineering) ;
  • Jang, Youn-Seon (Chungnam National University Department of Electronics Engineering)
  • Received : 2014.07.24
  • Accepted : 2014.09.11
  • Published : 2014.10.31

Abstract

WAVE (Wireless Access in Vehicular Environments) communications is the core technology for C-ITS (Cooperative-Intelligent Transportation System) which communicates with the road infrastructure and other vehicles to exchange traffic information and service while driving. In this paper, to analyze the performance degradation according to the distance between WAVE communication terminals, we derived the formulas for the locations of down-fade and up-fade points by using the two-ray ground reflection model, and verified these theoretical results by comparing with those of RSSI (Receiver Signal Strength Indicator) measurements. In addition, to solve the problem of down-fade, we suggested the WAVE communication with the antenna diversity and experimentally confirmed the performance improvement in the highway LOS (Line Of Sight) environments.

WAVE (Wireless Access in Vehicular Environments) 통신은 차량이 주행하면서 도로 인프라 및 다른 차량과 상호 통신하며 교통정보 및 서비스를 교환 및 공유하는 정보통신 융합 시스템인 국내 C-ITS (Cooperative-Intelligent Transportation System)의 핵심적인 기술이다. 본 논문에서는 고속도로에서의 WAVE 통신에 있어서 통신거리에 따라 통신성능이 현저히 떨어지는 null 점의 발생 위치를 분석하기 위하여 two-ray 지면 반사 모델을 사용하여 down-fade와 up-fade가 발생하는 위치를 수식으로 정의하였으며 실제 고속도로 LOS (Line Of Sight) 환경에서 WAVE 통신 장치를 사용한 RSSI (Receiver Signal Strength Indicator) 값 측정 실험결과와 비교 검증하였다. 또한, down-fade 발생의 문제점을 개선하기 위하여 수신 안테나 다이버시티 기능을 적용한 WAVE 통신 보드를 구현하고 실험을 통해 수신 성능이 개선되는 것을 확인하였다.

Keywords

References

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