In a mobile communication system, a mobile device wishing to access a cell first undertakes a cell search procedure. In a mobile communication system, such as LTE, the cell search procedure comprises a series of synchronization stages by which the mobile device (UE in the terminology of LTE) determines time frequency parameters that are necessary to demodulate the downlink and to transmit uplink symbols with the correct timing. Specifically, each cell in the system needs to be uniquely identified if the mobile device wishes to connect to a cell or if the mobile device is already connected to a cell but wishes to connect to another LTE cell. The latter scenario is referred to as a handover. For this purpose the base station transmits its cell-id within downlink data. The cell-id of the base station is detected by the mobile device when performing cell search. However, the handover procedure has problems in a cross sector scenario when the mobile device is moving in a fast speed as the cell-id detection takes some time resulting in a call drop. The cell-id of an adjacent cell to which the mobile device wishes to connect cannot be easily detected in advance to crossing the sector boundary as the beam of the adjacent cell may not be visible to the mobile device due to sectored beam forming of the mobile station.
USPTO Backgrounds
USPTO Backgrounds