There is provided a method comprising, in an antenna array comprising a plurality of antenna elements for use in a multiple-input multiple-output system, using at least one receiver for reception of at least one first signal by at least one of the plurality of antenna elements and using at least one first transceiver for at least one of transmission and reception of at least one second signal by at least one of the plurality of antenna elements, wherein the at least one receiver operates using at least one of a lower accuracy and a narrower bandwidth relative to the at least one first transceiver.