Decision Feedback Channel Estimation for OFDM with STTD

Abstract— In this paper, we propose decision feedback channel estimation (DFCE) for orthogonal frequency division multiplexing (OFDM) with space-time coded transmit diversity (STTD). Two transmit channels are simultaneously estimated by transmitting the STTD encoded pilot. To improve the tracking ability of the channel estimation against fast fading, decision feedback is also used in addition to pilot. For noise reduction and prevention of error propagation, the cascade of two averaging filters in timeand frequency-domain is applied. The average bit error rate (BER) performance of OFDM with STTD is evaluated by computer simulation. It is found that the use of DFCE can achieve a degradation in the Eb/N0 from ideal CE of as small as 2dB for an average BER=10. With receive antenna diversity reception, Eb/N0 degradation can be further reduced to as small as 1dB.

[1]  T.A. Thomas,et al.  Cyclic-prefix CDMA with antenna diversity , 2002, Vehicular Technology Conference. IEEE 55th Vehicular Technology Conference. VTC Spring 2002 (Cat. No.02CH37367).

[2]  Fumiyuki Adachi,et al.  Channel Estimation Filter Using Time-Multiplexed Pilot Channel for Coherent RAKE Combining in DS-CDMA Mobile Radio , 1998 .

[3]  Siavash M. Alamouti,et al.  A simple transmit diversity technique for wireless communications , 1998, IEEE J. Sel. Areas Commun..

[4]  Fumiyuki Adachi,et al.  Joint Frequency-Domain Equalization and Antenna Diversity Combining for Orthogonal Multicode DS-CDMA Signal Transmissions in a Frequency-Selective Fading Channel , 2004 .

[5]  S. Sampei,et al.  Rayleigh fading compensation for QAM in land mobile radio communications , 1993 .

[6]  Fumiyuki Adachi,et al.  Joint Space-Time Transmit Diversity and Minimum Mean Square Error Equalization for MC-CDMA with Antenna Diversity Reception , 2004 .

[7]  W. C. Jakes,et al.  Microwave Mobile Communications , 1974 .

[8]  H. Ochi,et al.  A Transmitter Diversity Scheme Based on the Space-Time Block Coding for Coded OFDM System , 2003 .

[9]  Steven D. Gray,et al.  Transmit diversity in 3G CDMA systems , 2002, IEEE Commun. Mag..

[10]  Hamid Jafarkhani,et al.  A differential detection scheme for transmit diversity , 2000, IEEE Journal on Selected Areas in Communications.

[11]  Leonard J. Cimini,et al.  Analysis and Simulation of a Digital Mobile Channel Using Orthogonal Frequency Division Multiplexing , 1985, IEEE Trans. Commun..

[12]  Fumiyuki ADACHI,et al.  Space-Time Transmit Diversity Combined with Frequency-domain Equalization for Single-carrier Transmission , 2003 .