Performance Analysis of DS/CDMA Hierarchical Cellular System on Shadowing and Imperfect Power Control

전파음영과 불완전 전력제어를 고려한 DS/CDMA 계층 셀룰라 시스템의 성능 분석

  • 윤석재 (김남 충북대학교 정보통신공학과 컴퓨터정보통신 연구소) ;
  • 김항래 (김남 충북대학교 정보통신공학과 컴퓨터정보통신 연구소)
  • Published : 2001.12.01

Abstract

In this paper, the capacity for the reverse link of the imperfect power controlled DS/CDMA hierarchical cellular system is analyzed considering imperfect sectorization in shadowing environment. Unlike the theoretical assumption, the power control of the DS/CDMA hierarchical cellular system is not perfect. Therefore, we consider various parameters such as the imperfect power control, the imperfect sectorization, the processing gain and the number of microcell interferers, which cause the capacity variation of the DS/CDMA hierarchical cellular system. It is shown that the capacity of DS/CDMA hierarchical cellular system is decreased according to the increase of the deviation of the imperfect power control, the overlapped angle, the power ratio between macrocell and microcell and to the decrease of processing gain, the number of microcell interfering users. Also, it is observed that the hierarchical cellular system can increase the user capacity from 1.54 to 3.89 times compared to the homogeneous macro-cellular system.

본 논문에서는 역방향 링크상의 전파 음영 채널에서 불완전 전력제어 및 불완전 섹터화를 고려하여 DS/CDMA 계층 셀룰라 시스템의 용량을 분석한다. 실제 시스템에서는 이론과는 달리 완전한 전력제어가 되지 않기 때문에 불완전 전력제어, 불완전 섹터화 및 처리이득, 매크로셀의 사용자 수와 같은 파라미터를 고려하여 시스템의 용량 변화를 유도하였다. 해석한 결과, 전력제어 및 섹터화가 불완전 할수록, 매크로셀과 마이크로셀의 전력비가 커질수록, 처리이득이 작을수록, 마이크로셀의 사용자 수가 감소할수록 DS/CDMA 계층 셀룰라 시스템의 용량은 감소하였다. 또한, 계층셀 구조가 단일 매크로셀 구조에 비해 1.54 배에서 3.89 배로 사용자 용량을 증가시킬 수 있음을 보였다.

Keywords

References

  1. IEEE Trans. Veh. Tech. v.40 no.2 On the capacity of a cellular CDMA system K. S. Gilhousen(et al.)
  2. IEEE Trans. Veh. Tech. v.44 no.1 Capacity, throughput, and delay analysis of a cellular DS-CDMA system with imperfect power control and imperfect sectorization M. G. Jansen;R. Prasad
  3. IEEE J. on Selected Areas in Communications v.11 no.6 Erlang capacity of a power controlled CDMA system M. Viterbi;A. J. Viterbi
  4. GLO-BECOM'95 Conf. On the Erlang capacity of CDMA cellular system J. S. Lee;L. E. Miller
  5. IEEE J. on Selected Areas in Communications v.11 no.6 A microcell/macrocell cellular architecture for low- and high-mobility wireless users C. L. I;L. J. Greenstein;R. D. Gitlin
  6. IEICE Trans. Fundamentals v.E81-A no.7 Spectrum resources management on two-tier cellular net-works I. Bazar;Y. Onozato
  7. IS-95 Standard Mobile station-base station compatibility standard for dual-mode wideband spread spectrum cellular system TIA/EIA
  8. IEEE J. on Selected Areas in Communications v.12 no.4 The capacity achievable with a broadband CDMA microcell underlay to an existing cellular macrosystem D. M. Grieco
  9. IEE Electron. Lett. v.32 no.20 Approximate interference of a microcellular spread spectrum system J. Wang;L. B. Milstein
  10. Wireless Communications T. S. Rappaport
  11. IRE Trans. on Commun. Systems v.C5-8 The sum of log-normal probability distributions in scatter transmission systems L. F. Fenton
  12. IEEE Veh. Tech. Conf. v.1 Improved performance assessment for a CDMA system in macro- and micro-cellular environments R. Prasad;H. S. Misser;P. H. Sinaga
  13. IEEE Commun. Mag. Multitier cell design X. Lagrange
  14. Third generation mobile communication systems R. Prasad;W. Mohr;W. Konhauser