A method of allocating resource elements in an orthogonal frequency division multiplexed (OFDM) system for transmission of a channel state information reference signal (CSI-RS) is disclosed. The method includes converting one or more resource elements to a two-dimensional frequency-time domain; and partitioning the one or more converted resource elements to units of a physical resource block (PRB). One or more resource elements are patterned over at least a portion of the PRB for transmission of the CSI-RS. According to an embodiment, the CSI-RS resource elements with a same subcarrier index for a common cell are code division multiplexed (CDM), with a CDM dimension equal to a number of CSI-RS resource elements with the same subcarrier index for the common cell.