A method of spatial modulation and associated transmission apparatus, receiver apparatus, computer program product and system for identifying a transmitter element within a transmission array of at least two transmitter elements, wherein a signal is transmitted by one active transmitter element at a time over a channel to a receiver. Power is allocated to the transmitter elements, wherein the power is allocated differently between at least two transmitter elements. The transmitted data is received at the receiver. The location of the active transmitter element is detected using knowledge of the power allocated to the transmitter elements.