System and method for acuiring cell in a frequency overlay communication system

The present invention relates to a frequency overlay communication system of the second frequency band including the first frequency band, the first frequency band exists, a system for performing cell acquisition, the predetermined sequence at a predetermined frequency band used to generate a reference signal to separate the cells, and distinguish that the base station receives the base station transmitting the reference signal, the reference signal using the first frequency band or the second frequency band, that is that the pre- through correlation with at least one sequence determining a reference signal having a maximum correlation value, and a mobile station for detecting a base station identifier corresponding to the detected reference signal. Frequency overlay, narrowband, broadband, cell acquisition, BS identification,