Frequency offset estimation with ambiguity of symbol timing offset for IEEE 802.16D OFDM system

Abstract

This paper presents a frequency synchronization scheme for OFDM mode in the IEEE 802.16d standard. Estimation range of fractional frequency offset (FFO) is derived based on the preamble structure. A novel algorithm with Double Sliding Windows Detection (DSWD) is proposed for integer frequency offset (IFO) estimation. The main idea behind this algorithm is to find the boundary of the data carriers and virtual carrers (VC) and calculate the energy ratio of the two consecutive sliding windows. Due to this feature, DSWD algorithm has the immunity to the ambiguity of symbol timing offset. Simulation results are assessed in terms of estimated frequency offset, probability of false alarm and bit-error-rate (BER) performance, which illustrate the efficiency of our proposed algorithm in the OFDM receiver.