A base station configured to operate in accordance with a periodically repeated synchronization period is provided. The synchronization period comprises a plurality of successive pilot slots, the pilot slots being associated with groups of base stations in a one-to-one relationship. The base station is configured to be a member of a first group among the groups of base stations and to transmit, in each repetition of the synchronization period, one or more pilot signals in the pilot slot associated with the first group.