Patent ID: 8923250

Claim:
A method of allocating a plurality of layers to a plurality of antenna ports in a wireless communication system, the method comprising: mapping the plurality of layers to the plurality of antenna port, respectively; mapping demodulation reference signals (DMRSs) of the plurality of layers to a first code division multiplexing (CDM) set or a second CDM set among radio resources and transmitting the DMRSs through the plurality of antenna ports; wherein the DMRSs mapped to a first CDM set in a first resource block (RB), from among the DMRSs of the plurality of layers, are mapped to a second CDM set in a second RB different from the first RB; the DMRSs mapped to a second CDM set in the first RB, from among the DMRSs of the plurality of layers, are mapped to a first CDM set in the second RB different from the first RB; wherein the first CDM set occupies a Resource Element (RE) allocated to first, sixth, and eleventh subcarriers of sixth and seventh Orthogonal Frequency Division Multiplexing (OFDM) symbols of each slot; the second CDM set occupies an RE allocated to second, seventh, and twelfth subcarriers of sixth and seventh OFDM symbols of each slot.