Patent ID: 7496160

Claim:
A frequency offset detection processing system comprising: a TCXO (Temperature Compensated Crystal Oscillator, Temperature Compensated X'tal Oscillator) which generates a reference frequency; a demodulation unit which demodulates a reception signal; a frequency offset detection unit which detects a frequency offset from a phase moving amount between symbols of adjacent pilot signals; and an AFC (Auto Frequency Control) control unit, characterized in that said AFC control unit comprises: a majority determination unit which determines whether each of phase moving amount detection values by a plurality of frequency offsets, which are detected for a predetermined time and read out from said frequency offset detection unit, is a positive value or a negative value, and totalizes to determine which of the positive values and the negative values are larger in number; a detection value conversion unit which converts the phase moving amount detection values read out from said frequency offset detection unit in accordance with a majority determination result from said majority determination unit, wherein said detection value conversion unit converts negative phase moving amount detection values to +360°+ the negative phase moving amount detection values when it is determined that a number of negative detection values is smaller than the majority determination result; and wherein said detection value conversion unit converts the positive phase moving amount detection values to −360°+ the positive phase moving amount detection values when it is determined that a number of positive detection values is smaller than the majority determination result; an averaging processing unit which executes processing for adding the phase moving amount detection values read out from said frequency offset detection unit and converted by said detection value conversion unit and dividing a sum by the number of added values; a correction value calculation unit which calculates a frequency offset from the phase moving amounts after averaging processing by said averaging processing unit; and a TCXO control unit which corrects TCXO control on the basis of the frequency offset calculated by said correction value calculation unit.