Patent ID: 8660084

Claim:
A method of transmitting a reference signal in a wireless communication system, the method comprising: generating demodulation reference signals (DMRSs) for each antenna of a plurality of antennas; mapping the DMRSs to a resource region; and transmitting each of the mapped DMRSs through a corresponding antenna of the plurality of antennas, wherein the DMRSs are multiplexed using at least frequency division multiplexing (FDM), code division multiplexing (CDM), or time division multiplexing (TDM) methods and mapped to the resource region, wherein a position of an orthogonal frequency division multiplexing (OFDM) symbol to which the DMRSs are mapped in the resource region is an OFDM symbol to which a physical downlink control channel (PDCCH) and a legacy cell-specific reference signal (CRS) are not mapped, wherein at least a portion of the DMRSs is multiplexed using the CDM method and mapped to two neighbor subcarriers within an OFDM symbol, and wherein the neighbor subcarriers are multiplexed using the CDM method based on an orthogonal sequence having a length of 2.