Assuming that the timing error detector 230 initially gets two data D1[(k)T2/2] and D1[(k+2)T2/2] (where k is an integer and T2 being the symbol period) to generate a timing metric M1, then the timing error detector 230 gets the next two data D1[(k+1)T2/2] and D1[(k+3)T2/2], which are respectively sampled with a T2/2 delay with respect to the former two data, to generate the next timing metric M2.