Systems and methods related to a synchronization signal particularly well suited for wireless devices in an extended coverage area of a cell of a cellular communications network are disclosed. In one embodiment, a base station transmits a synchronization signal including multiple repetitions of a basic synchronization block during a coherence time of a downlink channel over which the synchronization signal is transmitted. The multiple repetitions of the basic synchronization block during the coherence time enable coherent combining during detection of the synchronization signal at wireless devices located in the cellular communications network. This coherent combining enables, for example, wireless devices located in an extended coverage area of a cell served by the base station to synchronize to the cell using a shorter synchronization signal than that which would be required if only non-coherent combining were used.