Symbol Timing Estimation in Multiband Orthogonal Frequency Division Multiplexing based Ultrawide band System

Abstract

Problem statement: The Multiband Orthogonal Frequency Division Multiplexing (MB-OFDM) Based Ultra Wideband system (UWB) is highly susceptible to symbol timing error. Symbol timing estimation in MB-OFDM based UWB is difficult due to the presence of strongest path at delayed instant. Approach: Symbol timing estimation has two steps namely a coarse estimation and a fine estimation. In this study, a maximum likelihood framework for the fine timing estimation is proposed. It utilizes the delay embedded in the estimated Channel Impulse Response (CIR) obtained from the cross correlation of training sequence with the received sequence. Results: The performance of the proposed method is analyzed in terms of probability of correct timing detection. It is observed that the proposed technique has better probability of correct timing detection performance compared to the existing algorithm, in all the UWB channel models proposed by IEEE 802.15.3a working group for UWB systems. Conclusion: A novel method to estimate fine symbol timing error for MB-OFDM based UWB system is proposed. This method will be suitable for MB-OFDM receivers for UWB positioning and UWB communication.