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

한국통신학회 (The Korean Institute of Commucations and Information Sciences)
권호 표지

CDMA 시스템을 위한 Multistage Adaptive Partial PIC

Multistage Adaptive Partial PIC for CDMA System

  • 전재춘 (충북대학교 위성통신시스템연구실) ;
  • 이봉희 (충북대학교 위성통신시스템연구실) ;
  • 황인관 (충북대학교 위성통신시스템연구실)
  • 발행 : 2004.01.01
PDF 다운로드
⟨ 이전 논문 다음 논문 ⟩

초록

본 논문에서는 DS-CDMA 기반의 W-CDMA 상향링크 시스템에서 타사용자 간섭 및 다중 경로 간섭 신호를 효율적으로 제거할 수 있는 Multistage Adaptive Partial PIC를 설계하고 모의실험을 통해 그 성능을 분석하였다. 적응 방식은 연판정기의 가중치를 수신 신호에 따라 제어하는 방식이기 때문에 연판정의 효과를 극대화시킬 수 있고 더욱 정밀한 간섭 신호의 재생을 통해 검출 오류 포화 현상을 해결하여 우수한 성능을 얻을 수 있다. 결과적으로 Multistage Adaptive Partial PIC는 시변 특성의 다양한 채널환경에서 단순한 최적화 방법을 제공하고 기존 Multistage Partial PIC보다 적은 단계에서 최적성능을 보였다. 줄어든 단계이외에도 레이크 수신기의 출력단에서 간섭 신호를 제거하는 방식으로 설계하여 시스템의 복잡도를 대폭 줄였다. Multistage Adaptive Partial PIC를 사용함으로써 고속의 데이터 전송에서도 간섭 신호의 정밀한 재생과 효율적인 제거를 통해 초기 검출 오류로 인한 검출 오류 포화 현상을 해결하고 성능을 향상시킬 수 있음을 제시하였다.

In this paper, Multistage Adaptive Partial PIC eliminating effectively the multiple access and multipath interference for DS-CDMA based W-CDMA uplink system is designed and its performance is evaluated with computer simulation. By adaptively controlling the slope of the soft limiter with received signals, the efficiency of the soft limiter can be maximized and the better performance is obtained by solving error floor problem using further precise generation of interference signal. As a result, The proposed Multistage Adaptive Partial PIC with simple optimizing method for time-variant channel showed optimum performance at fewer stages. Besides fewer stages, the interference cancellation at the output of the rake receiver considerably reduced system complexity. The Multistage Adaptive Partial PIC with precise generation and efficient cancellation of interference signal can solve error eoor problem, resulted from initial false detection and improve system performance of high data rate system.

키워드

참고문헌

  1. Sergio. Verdu, Multiuser Detection, Cambridge University Press, 1998
  2. Tero. Ojanpera, 'Overview of Multiuser Detection/Interference Cancellation for DS-CDMA', IEEE ICPWC' 97, pp.115-119, Dec. 1997
  3. Ruxandra Lupas and Sergio. Verdu, 'Linear Multiuser Detectors for Synchronous Code-Division Multiple-Access Channels', IEEE Transaction Information theory, vol.35, no.1, Jan. 1989
  4. Mahesh K. Varanasi and Behnaam Aazhang, 'Multistage Detection in Asynchronous Code-Division Multiple-Access Communications', IEEE Transaction on Communications, vol.38, no.4, pp.509-519, Apr. 1990 https://doi.org/10.1109/26.52662
  5. Mahdi Vlozaffaripour and Rahim Tafazolli, 'Multisensor Partial Parallel Interference Cancellation for UMTS Uplink', IEEE 3G Mobile Communication Technologies, no.477 pp.392-395, Mar. 2001
  6. Sunghwan Kim and JaeHong Lee, 'Performance of Iterative Multiuser Detection with a Partial PIC Detector and Serially Concatenated Codes', IEEE Vehicular Technology Conference, vol.1, pp.487-491, Oct. 2001
  7. Slavica Marinkovic, Branka Vucetic, and Akihisa Ushirokawa, 'Space-time Iterative and Multistage Receiver Structures for CDMA Mobile Communication Systems', IEEE Journal, Selected Areas in Communications, vol.19, no.8, pp.1594-1604, Aug. 2001 https://doi.org/10.1109/49.942520
  8. Do-Sik Yoo andWayne E. Stark, 'Interference Cancellation for Multirate Multiuser Systems', IEEE Vehicular Technology Conference, vol.3, pp.1584-1588, May 2001
  9. Harry Holma and Antti Toskala WCDMA for UMTS, Wiley, 2000
  10. 3GPP, 'UMTS : Multiplexing and Channel Coding (FDD)', 3GPP TS 25.212, ver.4.2.0, Sep. 2001
  11. 3GPP, 'UMTS : Spreading and Modulation (FDD)' 3GPP TS 25.213, ver.4.1.0, Jun. 2001
  12. John G. Proakis, Digital Communications, 3rd ed., McGraw Hill, 1995
  13. Tao Xiaofeng, Li Lihua and Zhang Ping, 'Multistage non-linear parallel interference cancellation with small spread factor', Vehicular Technology Conference, 2001. VTC 2001 Spring IEEE VTS 53rd, vol.3, pp.1533-1537, May 2001
  14. Yue Heng Li, et al., 'A reduced complexity partial PIC detector', Vehicular Technology Conference, 2001. VTC 2001 Fall. IEEE VTS 54th, vo1.4, pp.2299-2303, Oct. 2001
  15. Bong Youl Cho, et al., 'Performance of the improved PIC receiver for DS-CDMA over Rayleigh fading channels', 2000 IEEE Sixth International Symposium on, vol.1, pp.45-49, Sep. 2000
  16. M. Mostofa, K. Howlader and Brian D. Woerner, 'Iterative interference cancellation and decoding using a soft cancellation factor for DS-CDMA', Vehicular Technology Conference Proceedings, 2000. VTC 2000-Spring Tokyo. 2000 IEEE 51st, vo1.3, pp.2076-2080, May 2000
  17. Chin Liang Wang, Kuo Ming Wu and Ming Shiang Lai, 'On weight initialization for adaptive multistage parallel interference cancellation in CDMA systems', 2001 IEEE Third Workshop on Signal Processing Advances in, pp.194-197, Mar. 2001
  18. N. Prapavong and W. Benjapolakul, 'Improvement of partial interference cancellation receiver using variance from matched filter for weight factor assignment and adaptation in multirate CDMA cellular mobile communication systems', 2001 IEEE Third Workshop on Signal Processing Advances in, pp.210-213, Mar. 2001
  19. Jeong Hoon Ko, Jung Suk Joo and Yong Hoon Lee, 'On the use of Sigmoid Functions for Multistage Detection in Asynchronous CDMA Systems', Vehicular TechnoIogy, IEEE Transactions on, vol.48, pp.522-526, Mar. 1999 https://doi.org/10.1109/25.752576
  20. Simon Haykin, Neural Network, 2nd ed., Prentice Hall, 2000
  21. 김대수, 신경망의 이론과 응용(I), (주)하이테크정보세계, 1999
  22. D. R. Hush and B. G. Horne, 'Progress in supervised neural networks', IEEE Signal Processing Magazine, vol.10, pp.8-39, Jan. 1993
  23. George I. Kechriotis and Elias S. Manolakos, 'Hopfield Neural Network Implementation of the Optimal CDMA Multiuser Detection', IEEE Trans. on Neural Networks, vol.7, no.1, pp.131-141, Jul. 1996 https://doi.org/10.1109/72.478397
  24. S.H. Yoon and S.S. Rao, 'Annealed Neural Network Based Multiuser Detector in codedivision Multiple Access Communications', IEEE Communications, vol.147, no.1, pp.57-62, Feb. 2000 https://doi.org/10.1049/ip-com:20000228
  25. H. Khoshbin-Ghomash, 'An adaptive neural network receiver for CDMA multi-user interference cancellation in multipath environments', Proc. of IEEE MILCOM '98, vol.3, pp.767-771, Mar. 1998