A sign-bit auto-correlation architecture for fractional frequency offset estimation in OFDM

This paper presents an architecture of an autocorrelator for Orthogonal Frequency Division Multiplexing systems. The received signal is quantized to only the sign-bit, which dramatically simplifies the frequency offset estimation. Hardware cost is reduced under the assumption that synchronization during acquisition does not have to be very accurate, but sufficient for coarse estimation. The architecture is synthesized towards a 65nm low-leakage high threshold standard cell CMOS library. The proposed architecture results in area reduction of 93% if compared to typical 8-bit implementation. The area occupied by the architecture is 0.063 mm2. The architecture is evaluated for WLAN, LTE and DVB-H. Power simulations for DVB-H transmission shows a power consumption of 4.8µW per symbol.

[1]  Babak Daneshrad,et al.  VLSI implementation for a low power mobile OFDM receiver ASIC , 2004, 2004 IEEE Wireless Communications and Networking Conference (IEEE Cat. No.04TH8733).

[2]  Xiaoyang Zeng,et al.  A robust and low complexity implementation of synchronization for DVB-T receiver , 2005, 2005 6th International Conference on ASIC.

[3]  Thomas Olsson,et al.  Performance Analysis of Sign-Based Pre-FFT Synchronization in OFDM Systems , 2010, 2010 IEEE 71st Vehicular Technology Conference.

[4]  M. Sandell,et al.  Low-complex frame synchronization in OFDM systems , 1995, Proceedings of ICUPC '95 - 4th IEEE International Conference on Universal Personal Communications.

[5]  T. Olsson,et al.  Sign-bit based architecture for OFDM Acquisition for multiple-standards , 2009, 2009 NORCHIP.

[6]  Antonio Torralba,et al.  Design of an efficient CORDIC-based architecture for synchronization in OFDM , 2006, IEEE Transactions on Consumer Electronics.

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

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