A novel carrier frequency offset estimation scheme for OFDM systems utilizing correlation with a pilot symbol without null sub-carrier

The orthogonal frequency division multiplexing (OFDM) carrier frequency offset estimation scheme is investigated. The carrier frequency offset is detected by monitoring a certain pattern of the frequency domain power differences along the sub-carriers of the pilot symbol. The power differences are raised by inter sub-carrier interference (ICI). In order to estimate the carrier frequency offset effectively, the time domain filtering (windowing) is carried out. The carrier frequency offset estimation performances corresponding to the pre-determined sequences which are transmitted as a pilot symbol are evaluated by computer simulations. Peak-to-average power ratio characteristics are also investigated. The results show that the proposed scheme is effective even for the frequency selective fading channel