| 摘要 |
The present invention relates to a method and an arrangement for synchronising communication of framed data via asynchronous base stations (BS1, BS2) in a cellular communications system, e.g. a CDMA-system. The synchronisation method is performed continuously by sending out certain system frame counter states from a central node in the system to all its connected base stations (BS1, BS2). Each base station (BS1, BS2) comprises a local frame counter (LFCBS1; LFCBS2), which generates local frame counter states (t1(1)-t1(4); t2(1)-t2(4)) correlated to the system frame counter states. Transmission of information via the base stations (BS1, BS2) is synchronised by assigning each data frame (DF(1)-DF(4)) a particular frame number, which is given by the local frame counter states (t1(1)-t1(4); t2(1)-t2(4)), so that data frames (DF(1)-DF(4)) having identical numbers are contain copies of a certain data packet. Correct frame numbers are derived from common downlink channel offset measurements (CCO1; CCO2) carried out in the base stations (BS1, BS2), and timing advance values (TA2) and downlink channel offsets (DCO1; DCO2) calculated in the central node. |
