The Journal of Korean Institute of Communications and Information Sciences (한국통신학회논문지)

The Korean Institute of Commucations and Information Sciences (한국통신학회)
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Performance analysis of multiple access mechanism based on error adaptation in CDMA cellular system

CDMA 셀룰러 시스템용 오율 적응 다중 엑세스 기법의 성능분석

  • 송상호 (경희대학교 전자계산공학과) ;
  • 조동호 (경희대학교 전자계산공학과)
  • Published : 1996.03.01
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Abstract

In recent, the demand of mobile communication system is increasing rapidly. However, since wireless resources is limitted, the protocol to utilize wireless resource efficiently is needed. Up to now, Slotted CDMA_ALOHA(S_CDMA_ALOHA) and Mini-Slotted CDMA_ALOHA(MS_CDMA_ALOHA) methods are proposed as a CDMA_ALOHA mechanism, and it is turned out that MS_CDMA_ALOHA offers betterperformance than S_CDMA_ALOHA mechanism. Also, IS-95 multiple access mechanism has been proposed as common air interface(CAI) protocol of CDMA digital cellular system. However, in former study, the performance evaluations were made without considertion of chnnel characteristics of wireless communication environment. In this paper, a new access mechanism for improring the performance in the DS/CDMA digital cellular environment is suggested. This mechanism is adaptive to the channel condition and based on the conventional MS_CDMA_ALOHA mechanism. Also, the performance of new access mechanism is compared with that of conventional mechanisms, through computer simulation. According tot h simulation results, it is shown that the proposed NA_CDMA_ALOHA(Noise-Adaptation CDMA_ALOHA) mechanism offers better performance than conventional three CDMA_ALOHA mechanisms in view of mean delay time and system throughput characteristics. This phenomenon is due to the fast that NA_CDMA_ALOHA mechanism controls the access attempts efficiently based on the channel condition in heavy traffic environments.

최근에 이동 통신의 수요가 급속히 증가하는 반면에 무선자원은 제한되어 있으므로 이를 효율적으로 이용할 수 있는 적합한 프로토콜이 요구되고 있다. 기존에 연구된 CDMA_ALOHA 기법중에 MS_CDMA_ALOHA(Mini Slotted CDMA_ALOHA) 방식이 S_COMA_ALOHA(Slotted COMA_ALOHA)보다 성능이 우수한 것으로 나타났다. 또한 CDMA 디지탈 셀룰러 시스템의 CAI 프로토콜로서 IS-95 다중 엑세스 방식이 제안되었다. 하지만 기존의 연구에서는 무선통신 환경의 채널특성을 고려한 성능분석이 이루어지지 않았다. 본 논문에서는 DS/CDMA 셀룰러 환경에서 성능개선을 위한 새로운 기법을 제시하였으며, 이는 기존의 MS_ COMA_ALOHA 방식을 기반으로 한 것으로서 채널상태에 적용할 수 있는 기법이다. 또한 컴퓨터 시뮬레이션을 통하여 기존의 방식과 비교 분석 하였다. 그 결과 새로 제안한 NA_COMA_ALOHA(Noise Adaptation COMA ALOHA) 방식은 기존의 COMA_ALOHA 방식보다 시스템 처리율 및 평균 지연특성면에서 우수한 성능을 보였다. 이는 NA_COMA_ALOHA 방식이 시스템의 과부하 환경에서 채널상태에 따라 사용자의 액세스 시도를 제어 하기 때문이다.

Keywords

References

  1. IEEE Trans. Comm. v.COM-30 no.5 Theory of Spread_Spectrum Communication-A Tutorial R. I. Pickholtz
  2. IEEE Trans. on Veh. Technol. v.40 no.2 On the Capacity of a Cellular CDMA System K. S. Gilhousen, et al.
  3. IEEE. JSAC v.10 no.6 Spread lotted ALOHA Techniques for Mobile and Personal Satelite Communication Systems Dimitrios Makrahis
  4. IEEE Trans. on Comm. v.COM-25 no.8 Performance Evaluation for Phases-Coded pread-Spectrum Multiple Access Communication Part2:Code Sequence Analysis M. B. Pusrsley;D. V. Sarwate
  5. IEEE. on Comm. v.39 no.6 The Effect of Capture on Performance of Multichannel Slotted ALOHA Systems Wuyi Yue
  6. IEEE Trans. on Comm. v.Com-20 no.6 The Performance of Random Access Packet Switched Code Division Multiple Access Systems D. Raychaudhuri
  7. IEEE. JSAC v.SAC-5 no.5 Perfect-Capture ALOHA for Local Radio Communication B. Ramamurthi, et al.
  8. IEEE. JSAC v.SAC-2 no.4 Analysis of Mobile Radio Slotted ALOHA Networks Christian Namislo
  9. IEEE VTC. '93 Performance Analysis and Simulation of Code Division Multiple Access Cellular Digital Network Zhenshong Zhang, et al.
  10. JCCI'93 v.3 셀룰러 DS/CDMA시스템의 성능분석 안병양;박상규
  11. TIA/EIA Interiim Standard IS-95