Modified nonlinear least square approaches to carrier frequency offset estimation in OFDM systems

Two modified nonlinear least square (NLS) estimators for carrier frequency offset (CFO) in orthogonal frequency-division multiplexing (OFDM) systems are proposed. In the modified NLS CFO estimators, slot elements in an OFDM block symbol are weighted in terms of their received energies. Simulation results show that the proposed new estimators outperform the original one especially in a low signal-tonoise ratio range.