Abstract—This paper proposes one integer frequency offsetestimation algorithm for orthogonal frequency divisionmultiplexing (OFDM) based digital radio mondiale (DRM)system. The algorithm exploits the correlation of frequencypilots to construct a novel angle vector. As the power factor ofthe pilots in the correlated calculation is inevitably disturbed bythe multipath and noise, the angle vector only utilizes the phasefactor of the pilots. The integer frequency offset can be obtainedby detecting the shift of the vector norm of the pilots, becausethe vector norm is maximum at the position of the pilots. Theperformance of the proposed algorithm is compared with that ofconventional algorithms. The simulation results show that theproposed algorithm can effectively combat multipath and noisewith wider range and higher accuracy of the frequency offsetestimation.