Patent ID: 7103827

Claim:
A start position detection method of receiving a cyclic code sequence with a code length n and detecting a start position of the cyclic code sequence, comprising the steps of: inputting a cyclic code sequence C i (i=1, 2, . . .) with a code length n bit by bit; generating an i-th code polynomial by adding a C i−1+n to an (i−1)-th syndrome polynomial and shifting a result of addition; generating an i-th remainder polynomial by dividing the i-th code polynomial by a generator polynomial; generating an i-th syndrome polynomial by subtracting a predetermined polynomial from the i-th remainder polynomial if a value of a preceding position C i−1 equals 1; determining whether or not the i-th syndrome polynomial equals 0; and detecting C i as the start position of the cyclic code sequence with the code length n if the i-th syndrome polynomial equals 0.