Patent ID: 7894554

Claim:
A method of performing downlink frame synchronization in a mobile terminal of a mobile communication system, the method comprising: obtaining phase shift values, wherein each of the phase shift values are obtained between a downlink synchronization code and a midamble code included in each of M number of consecutive subframes received from a base station; calculating a complex inner product between a reference vector representing M number of reference phase values and a phase vector representing M number of the obtained phase shift values; detecting a frequency offset between the base station and the mobile terminal; and performing the frame synchronization using the calculated complex inner product, wherein the frame synchronization is performed in accordance with a result of comparing a real part of the calculated complex inner product and a predetermined threshold value if the frequency offset is equal to or lesser than a reference value, and wherein the frame synchronization is performed using an imaginary part of the calculated complex inner product if the frequency offset is greater than the reference value.