Modified guard band power detection methods for OFDM frequency offset recovery

Fast and less complexity of modified guard band power detection (GPD) methods for orthogonal frequency division multiplexing (OFDM) coarse carrier offset estimation are presented. Conventional GPD have to be operated after the fine carrier offset recovery. The performance of GPD estimation may be significant degraded due to the induced interchannel interference (ICI) if fine carrier offset is not zero. In the paper, we first show that the accuracy of GPD estimation can be significant improved based on a simple concept of power average. Furthermore, according to the similar idea of reference symbol power adjustment (RPA), two general patterns of subcarrier power adjustment are presented to improve the estimation performance under nonzero fine frequency offset. Based on the simulation results of four COST 207 fading channel models, it is illustrated that the presented modified GPD methods can be operated independent of the fine carrier offset adjustment.