Pilot-aided carrier frequency offset estimation for OFDM systems

The paper proposes novel carrier frequency offset estimation algorithm that exploits scattered pilot symbols used for channel estimation of OFDM systems. Carefully designed pilot symbols can be incorporated to form null subcarriers by trivial manipulation of the received OFDM signals so that null subcarrier based maximum likelihood CFO estimation method can be applied, whereas conventional maximum likelihood CFO estimation using pilot symbols jointly estimates CFO and channel impulse response iteratively which is impractical. Simulation results show satisfactory performance for frequency tracking stage. The paper also provides reduced order polynomial rooting method for simple and fast CFO estimation.