A CELLULAR COMMUNICATION SYSTEM

摘要

A cellular communication system comprises a plurality of macrocells underlayed by a plurality of underlay cells. A scrambling code unit (113) comprises a subset processor (201) which divides a set of scrambling codes assigned to the underlay cells into distinct subsets. A scramble code group processor (203) assigns a scrambling code group comprising a plurality of scrambling codes to underlay cells within a region. Each group is a unique group within the region and comprises one scrambling code from each of the subsets. A base station (109) for each of the underlay cells is arranged to transmit a pilot signal on each scrambling code of the group assigned to the underlay cell. Measurements by a remote station (111) may detect specific scrambling codes within each subset thereby allowing a detection of an underlay cell while using a reduced number of scrambling codes. Furthermore, a reduced neighbour list may be maintained.