Coarse frequency synchronization method and apparatus in OFDM system

摘要

An apparatus and method for performing coarse frequency synchronization in an orthogonal frequency division multiplexing (OFDM) receiver are provided. The coarse frequency synchronization apparatus in a frequency synchronizer of an orthogonal frequency division multiplexing (OFDM) receiver includes a buffer that receives a demodulated symbol and outputs a shifted symbol generated by cyclically shifting the symbol by a predetermined shift amount; a controller that determines the length of an summation interval according to a phase coherence bandwidth and a number of sub-bands into which the summation interval is divided, and generates and adjusts a symbol time offset according to the number of sub-bands; a reference symbol predistortion portion that generates a reference symbol whose phase is distorted by the symbol time offset; a counter that counts the shift amount; a partial correlation portion that receives the shifted symbol and the reference symbol and calculates a partial correlation value for each of the sub-bands; and a maximum value detector that calculates the shift amount where the partial correlation value is a maximum and outputs the same as an estimated coarse frequency offset value.