On the design of symbol timing recovery for WLAN OFDM systems

We present a simple and robust symbol timing recovery algorithm for OFDM systems, such as IEEE 802.11a/g. The algorithm is derived according to a maximum likelihood (ML) algorithm utilizing the cyclic extension or cyclic prefix (CP), which is appended in front of each OFDM symbol. Simulation results show that the performance of the proposed algorithm is better than the conventional ML algorithm in the additive white Gaussian noise (AWGN) channel and approaches to the ML algorithm in the Rayleigh fading channel. Furthermore, the implementation complexity is lower than that of the ML algorithm.

[1]  S. Weinstein,et al.  Data Transmission by Frequency-Division Multiplexing Using the Discrete Fourier Transform , 1971 .

[2]  Erik G. Larsson,et al.  Joint symbol timing and channel estimation for OFDM based WLANs , 2001, IEEE Communications Letters.

[3]  Sayfe Kiaei,et al.  Globally optimum ML estimation of timing and frequency offset in OFDM systems , 2000, 2000 IEEE International Conference on Communications. ICC 2000. Global Convergence Through Communications. Conference Record.

[4]  Per Ola Börjesson,et al.  ML estimation of time and frequency offset in OFDM systems , 1997, IEEE Trans. Signal Process..

[5]  Antoine Chouly,et al.  Maximum likelihood frequency detectors for orthogonal multicarrier systems , 1993, Proceedings of ICC '93 - IEEE International Conference on Communications.

[6]  R. Chang,et al.  A Theoretical Study of Performance of an Orthogonal Multiplexing Data Transmission Scheme , 1968 .

[7]  Heinrich Meyr,et al.  Frame synchronization of OFDM systems in frequency selective fading channels , 1997, 1997 IEEE 47th Vehicular Technology Conference. Technology in Motion.

[8]  Ahmet M. Kondoz,et al.  Digital Speech: Coding for Low Bit Rate Communication Systems , 1995 .

[9]  Zhigang Cao,et al.  Timing recovery for OFDM transmission , 2000, IEEE Journal on Selected Areas in Communications.