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A Channel Estimation Scheme using Early-late Doppler Compensator in uplink WCDMA system  

Choi, Jung-Hyun (이화여자대학교 정보통신학과)
Kim, Nak-Myeong (이화여자대학교 정보통신학과)
Publication Information
The Journal of Korean Institute of Communications and Information Sciences / v.27, no.1B, 2002 , pp. 90-98 More about this Journal
Abstract
To increase system capacity in WCDMA receiver, the coherent detection is an essential technology for recovering transmitted symbols correctly. For coherent detection, an accurate and fast channel estimation is required. In next generation mobile communication system, high frequency carriers are used, and high data rate services are provided for subscribers having high mobility. In this communication environment, however, the rapidly-changing doppler frequency degrades the quality of the transmitted signal a lot. In WCDMA system, the channel estimation is conducted using pilot channel and/or pilot symbols which are known to both transmitter and receiver. Some existing channel estimation algorithms utilize these information quite well, but the performance of channel estimation gets very poor in a complicated fading channel distorted by the doppler effect. In this paper, we propose a new channel estimation algorithm combining an early-late doppler compensator so that the doppler effect and the fading characteristics are compensated at the same time. By computer simulation, the proposed algorithm proved to be a much more efficient channel estimation method in the fast fading channel, even at reasonably low Eb/No.
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  • Reference
1 Harri Holma, Antti Toskala, WCDMA for UMTS, Wiley, 2000
2 H. Andoh, M. Sawahashi, and F.Adachi,'Channel estimation filter using time multi-plexed pilot channel for coherent RAKEcombining in DS-CDMA mobile radio,' IEICE TRANS. Vol E81-B. No. 7, pp.1517-1525,July, 1998
3 S.Abeta, Sawahashi, and F.Adachi, 'Adaptivechannel estimation for coherent DS-CDMAmobile radio using time multiplexed pilot andparallel pilot structure,' IEICE TRANS. VolE82-B. No. 9, pp.1505-1513, Sep., 1999
4 M.Sakamoto, and J.Huoponen, 'Adaptivechannel estimation with velocity estimator forW-CDMA Receiver,' IEEE VTC, pp.2024-2028, May, 2000
5 ITU-R, Guidelines for evaluation of radiotransmission technologies for IMT-2000,Recommendation ITU-R, M.1225, 1998
6 Heinrich Meyr, Marc Moeneclaey, Stefan A.Fechtel, Digital Communication Receivers:Synchronization, Channel Estimation, and Signal Processing, Wiley, 1997
7 Seokjun Ko, and Hyungjin Choi, 'Effect ofImperfect channel estimation on the perform-ance of pilot channel aided coherent DS-CDMA system over rayleigh fading multipathchannel,' IEICE TRANS. Vol. E83-B, No.3,pp.721-733, March, 2000
8 S. Abeta, M. Sawahashi, and F.Adachi, 'Per-fomance comparison between time multiplexedpilot channel and parallel pilot channel forcoherent RAKE combining in DS-CDMAmobile radio,' IEICE TRANS. Vol E81-B. No.7, pp.1417-1425, July, 1998
9 A.Popper, E.Bejjani, 'Frame oriented channelestimation for UTRA/FDD with LSE polynomial fitting,' ICC 2000, pp.2128-2132,July, 2000
10 S.Sampei, 'Rayleigh fading compensation forQAM in land mobile radio communications,'IEEE Trans., Vol, VT-42, pp. 137-147, May.1993
11 M.Usuda, and Y.Ishikawa, 'Optimizing thenumber of dedicated pilot symbols for forward link in W-CDMA system,' IEEE, VTC,pp.2118-2122, May, 2000