A method includes, in a mobile communication terminal, receiving a signal including multiple instances of a synchronization signal transmitted in multiple respective time periods, wherein each instance is precoded with a respective precoding scheme that is selected from a set of precoding schemes in accordance with a precoding alternation pattern. A subset of the instances of the synchronization signal is selected, in accordance with an instance selection pattern that ensures that at least one of the instances of the synchronization signal is received in the terminal with at least a predefined quality. Only the instances belonging to the selected subset are decoded.