Design of Modified Timing Offset Estimation in OFDM for Maintaining Orthogonality

This paper deal with the symbol timing issue of an OFDM system in fast varying channel. Symbol timing offset (STO) estimation is a major task in OFDM. Most of existing methods for estimating STO used cyclic prefix or training sequences. In this paper, we consider a new system for STO estimation using constant amplitude zero auto-correlation (CAZAC) sequences as pilot sequences in conjunction with fractional Fourier transform (FRFT). This method gives good results in terms of MSE in comparison with other known techniques and it is important for fast varying channel. MATLAB simulations are used to evaluate the performance of the proposed estimator. Index Terms – STO: Symbol Timing Offset, OFDM: orthogonal Frequency Division Multiplexing, MIMO: Multiple Input Multiple Output, CAZAC: Constant Amplitude Zero Auto Correlation, ISI: Inter Symbol Interference ,ICI: Inter carrier Interference.