Patent ID: 9603111
Date: 2017-03-21
CPC Classifications: H04W

Claim:
1. A radio communication system comprising: base stations that include a first base station and a second base station, the first base station performing radio communication using a first frequency band and covering a first cell that is identified by a first cell identity, the second base station performing radio communication using a second frequency band and covering a second cell that is identified by a second cell identity; and a user device that performs radio communication with each of the base stations, wherein the first base station includes: a first transmitting unit that transmits, at a first transmission timing, a first synchronization signal that corresponds to the first cell identity, which identifies the first cell covered by the first base station, wherein the second base station includes: a second transmitting unit that transmits an identification signal that corresponds to the second cell identity, which identifies the second cell covered by the second base station, wherein the user device includes: a cell searcher that detects the first transmission timing based on the first synchronization signal received from the first base station and performs timing-search processing that establishes synchronization with the first base station, wherein the first base station further includes: an information notifying unit that notifies the user device of synchronization state information related to a synchronization state between the first base station and the second base station and of frequency information related to an identification signal frequency that the second base station uses to transmit the identification signal, the identification signal frequency being included in the second frequency band, and wherein the cell searcher of the user device, based on the synchronization state information from the first base station, performs identifying processing on the identification signal frequency indicated by the frequency information to identify the second cell identity corresponding to the identification signal.