Blind block synchronization algorithms in cyclic prefix systems

In orthogonal frequency division multiplexing (OFDM) systems, symbol synchronization is a critical step for successful data transmission. While this task is done in most current systems by using training symbols, a few studies have been dedicated to solving the problem blindly, that is, where training symbols are not available. Blind symbol synchronization problem is especially important in many blind channel estimation algorithms in the literature which assume that OFDM symbol synchronization is perfect. In this paper, a broader version of the blind symbol synchronization problem is studied, namely, blind block synchronization in cyclic-prefix (CP) systems. The proposed algorithm for this broader problem covers the blind symbol synchronization problem in OFDM systems. Unlike previously reported algorithms which are based on obtaining sufficient statistics of received samples, the proposed algorithm is capable of identifying the correct block boundaries using much less received data in absence of noise. Simulation results of the proposed algorithm not only verify the declared property but also demonstrate improvement in accuracy of symbol synchronization over previously reported algorithms in presence of noise.

[1]  M. Calvo Ramon,et al.  Rapid prototyping of a test modem for terrestrial broadcasting of digital television , 1997 .

[2]  P. P. Vaidyanathan,et al.  New Algorithms for Blind Block Synchronization in Zero-Padding Systems , 2007, 2007 IEEE International Conference on Acoustics, Speech and Signal Processing - ICASSP '07.

[3]  John M. Cioffi,et al.  Blind OFDM symbol synchronization in ISI channels , 2002, IEEE Trans. Commun..

[4]  Pierre Duhamel,et al.  Subspace-based blind and semi-blind channel estimation for OFDM systems , 2002, IEEE Trans. Signal Process..

[5]  Park,et al.  H.263-based SNR Scalable Video Codec , 1997, 1997 International Conference on Consumer Electronics.

[6]  A. Palin,et al.  Enhanced symbol synchronization method for OFDM system in SFN channels , 1998, IEEE GLOBECOM 1998 (Cat. NO. 98CH36250).

[7]  Robert Bregovic,et al.  Multirate Systems and Filter Banks , 2002 .

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

[9]  P. P. Vaidyanathan,et al.  Subspace-Based Blind Channel Identification for Cyclic Prefix Systems Using Few Received Blocks , 2007, IEEE Transactions on Signal Processing.

[10]  Donghoon Lee,et al.  A New Symbol Timing Recovery Algorithm For OFDM Systems , 1997, 1997 International Conference on Consumer Electronics.