According to one embodiment, a method for transmitting signals to a receiver, performed by a transmitter including a plurality of antennas, includes: selecting a precoding matrix based on a multiplexing rate (R) by selecting R column vectors from a single matrix corresponding to a maximum multiplexing rate, wherein each column vector of a first precoding matrix corresponding to a first multiplexing rate is included as a part of column vectors of a second precoding matrix corresponding to a second multiplexing rate when the second multiplexing rate is greater than the first multiplexing rate; precoding the signals using the selected precoding matrix; and transmitting the precoded signals to the receiver.