A blind EM-based carrier frequency offset estimation algorithm for OFDM signals

Abstract

Orthogonal frequency-division multiplexing (OFDM) system is very sensitive to the synchronization errors in digital communications, which should be compensated at the receiver. In this paper, we proposed an expectation maximum (EM) based blind carrier frequency offset (CFO) estimation algorithm for OFDM signals. By utilizing the second-order cyclostationarity of OFDM signals, a blind frequency offset estimation method is introduced as the initialization of EM algorithm. Without any prior information of the received signal, this method can realize the blind CFO estimation of OFDM after a few iterative process. Simulation results show that the proposed algorithm can effectively estimate the CFO at moderate and high signal to noise rate (SNR).