Channel Estimation for BFDM/OQAM System in Dispersive Time-Varying Channels

Pulse-shaping OFDM is well-known that it performs well in a mobile environment comparing with conventional OFDM. However, in highly mobile environment intersymbol and intercarrier interferences (ISI/ICIs) increase and can no longer be neglected. These ISI/ICIs deteriorate the performance of the systems. Practically, proper channel equalization and estimation are needed for further improvement of the systems. In this paper, more general case, namely biorthogonal frequency division system based on offset QAM (BFDM/OQAM) is considered. We first derive analytical equations for the channel statistics. Further, we propose maximum-likelihood channel estimator and its low-complexity versions. The performance analysis shows that the estimators are robust against Doppler spread of the channels.

[1]  Helmut Bölcskei,et al.  Orthogonal Frequency Division Multiplexing Based on Offset QAM , 2003 .

[2]  Gitta Kutyniok,et al.  Wilson Bases for General Time-Frequency Lattices , 2005, SIAM J. Math. Anal..

[3]  Gerald Matz,et al.  Pulse-shaping OFDM/BFDM systems for time-varying channels: ISI/ICI analysis, optimal pulse design, and efficient implementation , 2002, The 13th IEEE International Symposium on Personal, Indoor and Mobile Radio Communications.

[4]  T. Yamazato,et al.  On the Second-order Statistics of the Channel Parameters for BFDM/OQAM Systems , 2005, 2005 2nd International Symposium on Wireless Communication Systems.

[5]  Jean-Claude Belfiore,et al.  A Time-Frequency Well-localized Pulse for Multiple Carrier Transmission , 1997, Wirel. Pers. Commun..

[6]  Geoffrey Ye Li,et al.  Robust channel estimation for OFDM systems with rapid dispersive fading channels , 1998, IEEE Trans. Commun..

[7]  Andreas F. Molisch,et al.  Nonorthogonal pulseshapes for multicarrier communications in doubly dispersive channels , 1998, IEEE J. Sel. Areas Commun..

[8]  Thomas Strohmer,et al.  Optimal OFDM design for time-frequency dispersive channels , 2003, IEEE Trans. Commun..

[9]  Mj Martin Bastiaans.  Gabor's expansion and the Zak transform for continuous-time and discrete-time signals : critical sampling and rational oversampling , 1995 .

[10]  Helmut Bölcskei,et al.  Discrete Zak transforms, polyphase transforms, and applications , 1997, IEEE Trans. Signal Process..

[11]  Gerald Matz,et al.  MMSE and adaptive prediction of time-varying channels for OFDM systems , 2005, IEEE Transactions on Wireless Communications.

[12]  Anders Vahlin,et al.  Optimal finite duration pulses for OFDM , 1996, IEEE Trans. Commun..