Synchronisation method for base stations

base station synchronization method in a system mobile radio telecommunication, wherein a first base station transmits a synchronization sequence comprising a first sequence followed by a second sequence, said first and second sequences forming a couple of complementary sequences, and at least one second base station performs the correlating said synchronization sequence with a replica of the first sequence and a replica of the second sequence, the correlation results being then summed to give a correlation signal providing an indication of synchronization. The first sequence is separated from the second sequence by a separation interval of predetermined length (2GP, 2E), so that the signal correlation has a correlation peak isolated in a time window.