Packet Acquisition for DS/CDMA-based LEO Satellite communication System

DS/CDMA 저궤도 위성 통신 시스템의 패킷 초기 동기 연구

  • 김동희 (연세대학교 전기컴퓨터 공학과) ;
  • 김영초 (연세대학교 전기컴퓨터 공학과) ;
  • 이상운 (연세대학교 전기컴퓨터 공학과) ;
  • 황금찬 (연세대학교 전기컴퓨터 공학과)
  • Published : 2000.05.01

Abstract

A divided matched filter-reference filter(MF-RF) technique for LEO satellite packet transmission is proposed to increase the packet throughput in the presence of severe Doppler shift and fading. To overcome the severe Doppler shift, the divided matched filter is adopted where the integration region of matched filter is divided and ouputs of divided matched filer are added to decide the correct pseudo-noise (PN) phase. To maintain the constant false alarm rate in time varying interference and fading channel, the adaptive threshold for acquisition is obtained from the reference filter. As a performance measure, average acquisition time and packet throughput are used, and the effets of the parameters, i.e., Doppler shift, chip energy to noise ratio, user velocity, standard deviation of shadowing, and preamble length are shown.

이 논문은 저궤도 이동 위성 통신에서 나타나는 심각한 도플러 천이와 페이딩을 극복하면서 패킷 전송효율을 증가시킬 수 있는 DS/CDMA 시스템의 초기동기기법으로 분할 정합 여파기/참조 여파기 기법을 제안한다. 정합여파기의 정합구간을 분할하는 분할 정합여파기를 이용하여 극심한 도플러 천이를 극복하였으며, 참조여파기를 이용하여 시변하는 간섭과 페이딩에 강인한 초기동기를 이룰 수 있다. 성능분석의 척도로써 평균초기동기시간과 패킷 전송효율을 이용하며, 도플러 천이와 칩당 에너지대 잡음비, 사용자 이동속도, 음영 표준편차, 패킷 프리앰블내 심볼수 등과의 관계를 고찰한다.

Keywords

References

  1. IEEE J. Select. Areas Commun. v.14 no.9 Design Study for a CDMA-Based LEO Satellite Network: Downlink System Level Parameters S. G. Glisic;J. J. Talvitie;T. Kumpumaki;M. Latva-aho;J. H. Ilnatti;T. J Poutanen
  2. IEICE Trans. Fundamentals v.E80-A no.12 CDMA for Personal Comunications Based on Low Earth-Orbital Satellite Systems A. Ogawa;M. Katayama;T. Yamazato;A jamalipour
  3. IEICE Trans. Fundamentals v.E80-B no.9 On the Application of PN Acquisition Scheme to a DS/SSMA Packet Radio System J.Y. Kim;J. H. Lee
  4. IEEE Trans. Commun v.42 no.10 Acquisition of Timing and Doppler-Shift in a Direct Sequence Spread-Spectrum System A. W. Fuzjaeger;R. A. Iltis
  5. IEEE Trans. Commun. v.38 no.2 Spread-Spectrum Code Acquistition in the Presence of Doppler Shift and Data Modulation U. Cheng;W. J. Hurd;J. I. Statman
  6. IEEE Int. Sym. PIMRC v.1 A New Block Demodulator for DS/SS Signal with Carrier Frequency Offset S. Okuda;M. Katayama;T. Yamazato;A. Ogawa
  7. IEEE Trans. Commun. v.38 no.7 Direct Sequence Spread-Spectrum Parallel Acquisition in a Fading Mobile Channel E. A Sourour;S. C. Gupta
  8. IEEE J. Select. Areas Commun v.12 no.5 Direct Sequence Spread Spectrum Matched Filter Acquisition in Frequency-Selective Rayleigh Fading Channels B. B. Ibrahim;A. H. Aghvami
  9. IEEE J. Select. Areas Commun v.14 no.3 Rapid Acquisition Algorithm for Synchronization of Bursty Transmissions in CDMA Microcellular and Personal Wireless Systems W. A. Krzymien;A. Jalali;P. Mermelstrein
  10. IEICE Trans v.J79-A no.1 A New Code Acquisition Scheme Using Divided Matched Filters for DS/SS Signal with Frequency Offset M. Mizutani;M. Katayama;T. Yamazato;A. Ogawa