Patent ID: 8867669

Claim:
A circuit for removing a frequency offset of a baseband signal, the circuit comprising: a sampling circuit for sampling a frequency level of the baseband signal at every 0.5 symbol interval to obtain a sequence of sample levels; a first difference absolute value calculating part for calculating first absolute values of differences between the frequency levels adjacent to each other at every 1 symbol based on an arbitrary first frequency level of the sample levels as a plurality of first difference absolute values; a second difference absolute value calculating part for calculating second absolute values of differences between the frequency levels adjacent to each other at every 1 symbol based on a second frequency level of the sample levels after 0.5 symbol from the first frequency level as a plurality of second difference absolute values; an average calculating part for calculating an average value of the sequence of the sample levels used for calculating the first and second difference absolute values; and a frequency offset holding part for setting the average value calculated by the average calculating part into the frequency offset when the first difference absolute values are greater than a predetermined first determination value or the second difference absolute values are less than a predetermined second determination value.