METHOD AND APPARATUS FOR CARRIER FREQUENCY OFFSET ESTIMATION USING SAGE TECHNIQUE IN OFDMA SYSTEM

摘要

PURPOSE: A method and apparatus for estimating a carrier frequency offset using SAGE(Space Alternating Generalized Expectation-Maximization) technique in an orthogonal frequency division multiplexing access system are provided to access a CRB(Cramer Rao bound) of a theoretically optimal value by comparing a suggested SAGE algorithm with a conventional SAGE algorithm. CONSTITUTION: An expectation of a complete signal is generated by eliminating MU(Mobile Unit) signals from received signals except for any MU signals. The generated expectation of the complete signal is transformed by FFT(Fast Fourier Transform). An approximation of a FFT output is calculated from the expectation of the complete signal. Residual CFOs(Carrier Frequency Offset) are obtained using the approximation of the FFT output, a training sequence signal received to a subcarrier, and a leakage signal. A CFO is estimated using the residual CFO.