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Performance Analysis of Assisted-Galileo Signal Acquisition Under Weak Signal Environment

약 신호 환경에서의 Assisted-Galileo 신호 획득 성능 분석

  • Lim, Jeong-Min (Department of Information and Communication Engineering, Chungnam National University) ;
  • Park, Ji-Won (Instrumentation and Control and Human Factors Research Division, Korea Atomic Energy Research Institute) ;
  • Sung, Tae-Kyung (Department of Information and Communication Engineering, Chungnam National University)
  • 임정민 (충남대학교 전자전파정보통신공학과) ;
  • 박지원 (한국원자력연구원 계측제어인간공학연구부) ;
  • 성태경 (충남대학교 전자전파정보통신공학과)
  • Received : 2012.08.09
  • Accepted : 2013.05.16
  • Published : 2013.07.01

Abstract

EU's Galileo project is a market-based GNSS (Global Navigation Satellite System) that is under development. It is expected that Galileo will provide the positioning services based on new technologies in 2020s. Because Galileo E1 signal for OS (Open Service) shares the same center frequency with GPS L1 C/A signal, CBOC (Composite Binary Offset Carrier) modulation scheme is used in the E1 signal to guarantee interoperability between two systems. With E1 signal consisting of a data channel and a pilot channel at the same frequency band, there exist several options in designing signal acquisition for Assisted-Galileo receivers. Furthermore, compared to SNR worksheet of Assisted-GPS, some factors should be examined in Assisted-Galileo due to different correlation profile and code length of E1 signal. This paper presents SNR worksheets of Galileo E1 signals in E1-B and E1-C channel. Three implementation losses that are quite different from GPS are mainly analyzed in establishing SNR worksheets. In the worksheet, hybrid long integration of 1.5s is considered to acquire weak signal less than -150dBm. Simulation results show that the final SNR of E1-B signal with -150dBm is 19.4dB and that of E1-C signal is 25.2dB. Comparison of relative computation shows that E1-B channel is more profitable to acquire the strongest signal in weak signal environment. With information from the first satellite signal acquisition, fast acquisition of the weak signal around -155dBm can be performed with E1-C signal in the subsequent satellites.

Keywords

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