Design of an efficient CORDIC-based architecture for synchronization in OFDM

This paper presents a new architecture to estimate the time and frequency offsets required to synchronize packed-based orthogonal frequency division multiplexing (OFDM) modulation receivers. The proposed estimators, which operate in the frequency-domain, use CORDIC (coordinate rotation digital computer) processors to achieve an efficient hardware implementation which is simpler than other computational intensive estimators based on processing in the time-domain. The hardware saving is twofold: the proposed implementation does not require complex cells such as multipliers or dividers; and some cells already existing in OFDM receivers for pay-load demodulation are reused during the synchronization phase. In addition, this paper also shows how to optimize the CORDIC cells, in terms of number of iterations, to provide a given signal-to-noise ratio (SNR) due to approximation error, and proposes an error propagation model for the proposed synchronization architecture

[1]  Young-Hwan You,et al.  Frequency-offset synchronization and channel estimation for OFDM-based transmission , 2000, IEEE Commun. Lett..

[2]  Hwang Soo Lee,et al.  Decision-directed maximum-likelihood estimation of OFDM frame synchronisation offset , 1994 .

[3]  Robert W. Brodersen,et al.  Synchronization schemes for packet OFDM system , 2003, IEEE International Conference on Communications, 2003. ICC '03..

[4]  L. Hanzo,et al.  Adaptive multicarrier modulation: a convenient framework for time-frequency processing in wireless communications , 2000, Proceedings of the IEEE.

[5]  Heinrich Meyr,et al.  Optimum receiver design for OFDM-based broadband transmission .II. A case study , 2001, IEEE Trans. Commun..

[6]  Yu Hen Hu,et al.  The quantization effects of the CORDIC algorithm , 1992, IEEE Trans. Signal Process..

[7]  Sang Yoon Park,et al.  Fixed-point error analysis of CORDIC processor based on the variance propagation formula , 2004, IEEE Transactions on Circuits and Systems I: Regular Papers.

[8]  Antonio Torralba,et al.  A new method for simultaneous fine time synchronization and frequency offset estimation in OFDM with simple hardware , 2003, GLOBECOM '03. IEEE Global Telecommunications Conference (IEEE Cat. No.03CH37489).

[9]  Joseph R. Cavallaro,et al.  Numerical Accuracy and Hardware Tradeoffs for CORDIC Arithmetic for Special-Purpose Processors , 1993, IEEE Trans. Computers.

[11]  Paul H. Moose,et al.  A technique for orthogonal frequency division multiplexing frequency offset correction , 1994, IEEE Trans. Commun..

[12]  H. Meyr,et al.  Optimum Receiver Design for OFDM-Based Broadband Transmission — Part II : A Case Study , 2001 .

[13]  Antonio Torralba,et al.  Method for frequency offset estimation in OFDM with application to power line communication , 2003 .

[14]  Y.H. Hu,et al.  CORDIC-based VLSI architectures for digital signal processing , 1992, IEEE Signal Processing Magazine.

[15]  Hui Zhang,et al.  Synchronization method based on a new constant envelop preamble for OFDM systems , 2005, IEEE Transactions on Broadcasting.

[16]  Donald C. Cox,et al.  Robust frequency and timing synchronization for OFDM , 1997, IEEE Trans. Commun..

[17]  Burton R. Saltzberg,et al.  Multi-Carrier Digital Communications: Theory and Applications of Ofdm , 1999 .