Low-complex frame synchronization in OFDM systems

Orthogonal frequency-division multiplexing (OFDM) systems have gained an increased interest due to their use in wireless applications such as mobile communication systems. A novel data-based frame synchronization method for OFDM-systems is presented. OFDM frames are shown to contain sufficient information to synchronize a system without the use of pilots. The cyclic extension, preceding OFDM frames, is of decisive importance for this method. Based on only the sign bits of the in-phase and the quadrature components of the received OFDM signal, the maximum likelihood solution is derived. This solution basically consists of a correlator, a moving sum and a peak detector. The stability of the generated frame-clock is improved significantly by averaging over a few number of frames. Simulations show that this low-complex, averaging method can be used to synchronize an OFDM system on twisted pair copper wires and in slowly fading radio channels.

[1]  H. Saunders,et al.  Probability, Random Variables and Stochastic Processes (2nd Edition) , 1989 .

[2]  Philippe J. Tourtier,et al.  Multicarrier modem for digital HDTV terrestrial broadcasting , 1993, Signal Process. Image Commun..

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

[4]  J.-J. Werner,et al.  The HDSL environment (high bit rate digital subscriber line) , 1991 .

[5]  D. Veeneman,et al.  Clipping distortion in DMT ADSL systems , 1993 .

[6]  U. Dersch,et al.  Propagation mechanisms in microcell and indoor environments , 1994 .

[7]  Athanasios Papoulis,et al.  Probability, Random Variables and Stochastic Processes , 1965 .

[8]  F. Daffara,et al.  A new frequency detector for orthogonal multicarrier transmission techniques , 1995, 1995 IEEE 45th Vehicular Technology Conference. Countdown to the Wireless Twenty-First Century.

[9]  J.A.C. Bingham,et al.  Multicarrier modulation for data transmission: an idea whose time has come , 1990, IEEE Communications Magazine.

[10]  Jean-Jacques Werner,et al.  The HDSL Environment , 1991, IEEE J. Sel. Areas Commun..

[11]  John M. Cioffi,et al.  Multi-tone transmission for asymmetric digital subscriber lines (ADSL) , 1993, Proceedings of ICC '93 - IEEE International Conference on Communications.

[12]  Cyril Leung,et al.  OFDM/FM frame synchronization for mobile radio data communication , 1993 .

[13]  M. Alard,et al.  Principles of Modulation and Channel Coding for Digital Broadcasting for Mobile Receivers , 1987 .

[14]  John M. Cioffi,et al.  Performance Evaluation of a Multichannel Transceiver System for ADSL and VHDSL Services , 1991, IEEE J. Sel. Areas Commun..