On the guard band-based coarse frequency offset estimation technique for burst OFDM systems

A multiple number of subcarrier frequency offsets is estimated in the frequency domain. This is achieved by adjusting the power of the reference symbol transmitted and utilizing a guard-band power detection method in the receiver. The power of the start symbol of two repetitive symbols, which also acts as a reference symbol in differential modulation, is varied linearly in the frequency domain to increase the power difference between modulated (valid) subcarriers and noisy non-modulated (virtual) carriers. The performance of the proposed frame is confirmed by simulation for a DQPSK system in a multipath-fading environment.