Low complexity channel estimation scheme for OFDM systems with the aid of dynamic pilots

This paper presents a low complexity channel estimation scheme for OFDM systems in multipath fading channels. The proposed scheme is designed based on the pilots, which are arranged at different locations for different OFDM symbols. In slow and moderate time-varying fading channels, the channel frequency response could be estimated accurately with simple linear interpolation. On the other hand, the number of embedded pilots is reduced using the proposed scheme. Ultimately, the channel frequency response of the current OFDM symbol is estimated from the current and neighboring pilots and no further calculation is required. The effects of the Doppler frequency on the proposed scheme are also considered in this paper. Computer simulations are conducted to evaluate the performance of the proposed scheme. It is shown that the performance of the proposed scheme is close to maximum likelihood (ML) algorithm in the time-varying fading channels

[1]  Ieee Microwave Theory,et al.  Part 16: Air Interface for Fixed and Mobile Broadband Wireless Access Systems — Amendment for Physical and Medium Access Control Layers for Combined Fixed and Mobile Operation in Licensed Bands , 2003 .

[2]  Fatin Said,et al.  Linear two dimensional pilot assisted channel estimation for OFDM systems , 1998 .

[3]  Dhammika Jayalath,et al.  Low-complexity channel estimation for wireless OFDM systems , 2003, 14th IEEE Proceedings on Personal, Indoor and Mobile Radio Communications, 2003. PIMRC 2003..

[4]  Yu Ted Su,et al.  Blind and semiblind detections of OFDM signals in fading channels , 2004, IEEE Transactions on Communications.

[5]  A. M. Abdullah,et al.  Wireless lan medium access control (mac) and physical layer (phy) specifications , 1997 .

[6]  Umberto Spagnolini,et al.  Adaptive pilot pattern for OFDM systems , 2004, 2004 IEEE International Conference on Communications (IEEE Cat. No.04CH37577).

[7]  Umberto Mengali,et al.  A comparison of pilot-aided channel estimation methods for OFDM systems , 2001, IEEE Trans. Signal Process..

[8]  Ye Li.  Pilot-symbol-aided channel estimation for OFDM in wireless systems , 1999, 1999 IEEE 49th Vehicular Technology Conference (Cat. No.99CH36363).

[9]  Robert W. Heath,et al.  Blind channel identification and equalization in OFDM-based multiantenna systems , 2002, IEEE Trans. Signal Process..

[10]  Zhigang Cao,et al.  Analysis of low-complexity windowed DFT-based MMSE channel estimator for OFDM systems , 2001, IEEE Trans. Commun..

[11]  Liesbet Van der Perre,et al.  A low-complexity ML channel estimator for OFDM , 2003, IEEE Trans. Commun..

[12]  M. Ergen,et al.  A study of channel estimation in OFDM systems , 2002, Proceedings IEEE 56th Vehicular Technology Conference.

[13]  Jean-Philippe Javaudin,et al.  Pilot-aided channel estimation for OFDM/OQAM , 2003, The 57th IEEE Semiannual Vehicular Technology Conference, 2003. VTC 2003-Spring..