A method and a device in a User Equipment (UE) and a base station used for wireless communication systems that support broadcast signals. The UE receives a first radio signal on a first time-frequency resource. The first radio signal comprises a first RS sequence, RSs in the first RS sequence are mapped from lower frequency to higher frequency in frequency domain, the first time-frequency resource belongs to a first frequency domain resource. The first frequency domain resource comprises K frequency domain sub-resource(s). (A) Position(s) of the K frequency domain sub-resource(s) in the first frequency domain resource is(are) unfixed, RSs of the first RS sequence in a given frequency domain sub-resource are not related to a position of the given frequency domain sub-resource in the first frequency domain resource. Therefore, the UE is able to correctly receive RSs even without knowing the position of frequency domain resources in the system bandwidth.