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

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

Performance analysis of an MC-CDMA system by using an adaptive beamforming technique

적응 빔 형성 기법을 사용한 MC-CDMA 시스템의 성능분석

  • 김찬규 (한국전자통신연구원 정회원) ;
  • 조용수 (중앙대학교 전자공학과 통신 및 신호처리 연구실 정회원)
  • Published : 1999.10.01
Download PDF
⟨ Previous Next ⟩

Abstract

This paper presents an adaptive beamforming algorithm for an MC-CDMA system with an adaptive array antenna. By employing an antenna array at the receiver of an MC-CDMA system, the performance of an MC-CDMA system, which is known to be effective for high data rate transmission due to its robustness to multipath fading and its simplicity for using a simple one-tap equalizer, is shown to be significantly improved. The proposed algorithm for adaptive beanforming in an MC-CDMA system is derived by (1) calculating the error signals between the pilot symbols of desired user and the received pilot signals in frequency domain, (2) transforming the frequency-domain error signals into time-domain error signals, (3) updating the filter coefficients of the adaptive beamformer in the direction of minimizing the MSE. Convergence behavior and performance improvement of the proposed approach are demonstrated through computer simulation by applying it to the conventional MC-CDMA system.

이 논문에서는 적응 배열 안테나를 갖는 MC-CDMA를 위한 적응 빔 형성 알고리듬을 제안한다. 다중경로 페이딩에 robust하고 간단히 단일 탭 등화기를 사용하여 고속 데이터 전송에 적합한 것으로 알려진 MC-CDMA 시스템의 수신단에 안테나 배열을 사용함으로서 그 성능을 크게 개선할 수 있음을 보인다. 본 논문에서 제안된 MC-CDMA 시스템의 적응 빔 형성 알고리듬은 원하는 사용자의 파이롯 심벌(기준신호)과 수신된 파이롯 신호의 오차를 주파수 영역에서 계산하고, 그 주파수 영역 오차신호를 시간영역 오차 신호로 변환한 후, MSE가 최소가 되는 방향으로 적응 빔 형성기의 계수를 갱신하므로서 유도된다. 모의 실험과 해석적 방법을 통하여 MC-CDMA 시스템에 제안된 적응 빔 형성기법을 적용할 경우 수렴특성과 성능개선 효과를 확인한다.

Keywords

References

  1. IEEE Trans. Veh Technol. v.40 no.2 On the capacity of a cellular CDMA system K.S Gilhousen;I. M. Jacobs;R. Padovani;A. Viterbi;L. A Weaver;C. Wheatly
  2. Proc. of PIMRC93 Multicarrier CDMA in indoor wireless radio networks N. Yee;J-P. Linnartz;G. Fettweis
  3. IEEE Commun. Magazine v.33 Transmission techniques for digital terrestrial TV broadcasting H. Sari;G.Karam;I. Jeanclaude
  4. Proc. of VTC96 DS-CDMA, MC-CDMA and MT-CDMA for mobie multimedia communications Shinuke Hara;Ramjee Prasad
  5. IEEE Trans. comm3 v.44 no.3 Performance of orthogonal multicarrier CDMA in a multipath fading channel Essam A. Sourour;Masao Nakagawa
  6. Proc. of VTC96 Performance Enhancement of DS-CDMA microcellular networks with adaptive antenas George V. Tsoulos;Mark A. Beach;Simon c. Swales
  7. IEEE Trans. Veh. Tech. v.VT-43 Analytical results for capacity improvement in CDMA J. C. Liberti;T. S. Rappaport
  8. Proc. of PIMRC A hardware testbed for evaluation of adaptive antennas in GSM/UMTS Preben E. Mogensen;Frank Frederikesen
  9. IEEE Comm. Magazine Application of adaptive arrays antenna to a TDMA cellular /PCS system Vijay. K. Garg;Laura Huntington
  10. IEEE J. Selected Areas Comm v.14 no.9 Performance of wireless CDMA with M-ary orthogonal modulation cell cite antenna arrays A. F. Naguib;A. Paulraj
  11. Proc.of Statistical Signal And Arrays An LMS arrays for CDMA wireless communication systems Frank Fruth;Evaggelos Geraniots
  12. Proc. of ICASSP Adaptive antenna arrays for cellular CDMA communtication systems Yiping Wang;J. R. Cruz
  13. PrenticeHall Inc. Adaptive filter theory Simon Haykin
  14. Handbook of statistics 10, Signal Processing and its applications : Constrained Beamforming and Adaptive Algorithms N.K Bose;C.R. Rao;Lal;C. Godara
  15. Probability,Radom Variable, and Stochastic Process A. Papoulis