연판정 하이브리드 PN 코드 동기 획득 기법

Hybrid PN Code Search with Soft-decision Technique

  • 이성주 (세종대학교 정보통신공학과)
  • 발행 : 2006.07.01

초록

본 논문에서는 파일롯 채널(pilot channel)이 존재하는 직접확산 코드분할 다중접속 방식(DS-CDMA)에서 PN 코드의 초기 동기획득 성능을 개선하기 위해 연판정 기법을 사용하는 방법을 제안한다. 본 논문에서 제안하는 연판정 기법을 하이브리드 동기획득 알고리듬에 적용하고, 평균 동기획득 시간 측면에서 분석한다. 분석을 위해, 제안된 방식의 수학적 모델을 제시하고, IMT-2000 채널모델에서 시뮬레이션을 수행한다. 수식적인 분석 결과, 제안된 방식이 한 쌍의 임계치를 사용하는 기존 방식에 비해 평균 동기획득 시간에서 약 0.2초 내지 0.4초 정도의 성능향상을 가져오는 것을 보여준다. 이것은 연판정 기법이 기존의 경판정 기법의 사용으로 인한 성능열화를 보상함으로써 생기는 이득이라고 볼 수 있다.

In this paper, a soft-decision method for initial PN code acquisition in pilot-channel aided Direct Sequence Code Division Multiple Access (DS-CDMA) systems is proposed in order to improve the acquisition performance. We apply this technique to the conventional hybrid search algorithm and analyze it in terms of mean code acquisition time. For the analysis, we present mathematical model of proposed algorithm and also perform the simulation under IMT-2000 channel models. Numerical results show that our proposed scheme outperforms the conventional one by 0.2 - 0.4 sec with respect to the mean code acquisition time because the soft decision technique can mitigate the possible decline in search performance caused by the use of a hard-decision technique.

키워드

참고문헌

  1. K. S. Gilhousen, et al., 'On the capacity of a cellular CDMA system,' IEEE Trans. on Vehicular Tech., Vol. 40, No 2, pp.303-312, May 1991 https://doi.org/10.1109/25.289411
  2. Douglas N. Knisely, Sarath Kumar, Subhasis Laha, and Sanjiv Nanda, 'Evolution of Wireless Data Services: IS-95 to cdma2000,' IEEE Communications Magazine, pp. 140-148, October 1998
  3. W. C. Y. Lee, 'Spectrum and Technology of a Wireless Local Loop System,' IEEE Personal Comm., Vol.5, No.1, pp49-54, 1998. 2. 1 https://doi.org/10.1109/98.656162
  4. Had-Sock Oh, Dong-Seog Han, and Kil-Houm Park, 'Adaptive Double-dwell PN Code Acquisition in Direct-Sequence Spread-Spectrum Systems,' MILCOM2000, Vol.1, pp.139-143
  5. Rehan Ahmad Warsi and Ajit Kumar Chaturvedi, 'A New Adaptive Serial Search PN Code Acquisition Scheme for DS-SS Systems,' ICPWC2000, pp.245-248
  6. Young H. You, Hyoung R, Cho, Man S. Joo, and Chang E. Kang, 'Detection Technique for a serial DS-SS code synchronization in a fading mobile channle,' IEE Electronics Letters, Vol.33, No.6, pp446-447 https://doi.org/10.1049/el:19970345
  7. Laurence B. Milstein, John Gevargiz, and Pankaj K. Das, 'Rapid Acquisition for Direct Sequence Spread-Spectrum Communications Using Parallel SAW Convolvers,' IEEE Trans. on Comm., Vol. 33, No.7, pp. 593-600, July 1985 https://doi.org/10.1109/TCOM.1985.1096354
  8. Essam Sourour and Cupta. S. C, 'Direct sequence spread spectrum parallel acquisition in a fading mobile channel,' IEEE Trans. on Comm., Vol. 38, No.7, pp.992-998, 1990 https://doi.org/10.1109/26.57497
  9. Weihua Zhuang, 'An improved hybrid PN code acquisition for CDMA personal wireless communications,' Proceedings of PIMRC95, pp.995-999, May 1995
  10. Bub-Joo Kang, Hyung-Rae Park, Youngnam Han, 'Hybrid Acquisition in DS/CDMA Forward Link,' Proceedings of IEEE Vehicular Technology Conference, Vol.3-B, pp.2123-2127, May 1997
  11. Seongjoo Lee and Jaeseok Kim, 'Optimum Threshold for Double-dwell DS-SS Code Acquisition System in PCS Channel Model,' IEE Electronics Letters, Vol. 34, No.7, pp. 634-635, 1998 https://doi.org/10.1049/el:19980116
  12. Biqi Long and Hichan Moon, 'Detection and false alarm probability of PN code acquisition,' IEE Electronic Letters, Vol. 33, pp.926-927, May 1997 https://doi.org/10.1049/el:19970623
  13. ITU-R M.1225, 'Guidelines for Evaluation of Radio Transmission Technique for IMT-2000,' 1997
  14. Seongjoo Lee, Sangyun Hwang, and Jaeseok Kim, 'Low-complexity architecture of rake receiver for multi-code CDMA system,' IEE Electronics Letters, Vol. 34, No. 14, pp.1382-1383. 1998 https://doi.org/10.1049/el:19980990
  15. Andrew J. Viterbi, 'CDMA: Principles of Spread Spectrum Comm.,' Addison-Wesley Pub., 1995
  16. R. L. Peterson, R. E. Ziemer, and D. E. Borth, 'Introduction to Spread-Spectrum Communications,' Upper Saddle River, NJ: Prentice Hall, 1995
  17. A.W. Lam and S. Tantaratana, 'Theory and applications of spread-spectrum systems,' in IEEE, Inc., 1994. Study Guide