Superimposed training aided carrier frequency offset estimation in OFDM systems

In OFDM systems, orthogonality between subcarriers is impaired due to carrier frequency offset (CFO) and it must be compensated for in the receiver before DFT demodulation. In this paper, carrier frequency offset estimation is proposed for frequency selective slowly-varying channels. This algorithm utilizes the superimposed pilots and uses the correlation between the consequent OFDM symbol blocks because of periodic superimposed training added to the data. Compared to the previous algorithms, the spectral efficiency is higher in the proposed scheme. Simulations testify to the effectiveness of the proposed algorithm.