A method of wireless communication comprising: determining (205, 1605, 1705) a mapping configuration associated with a plurality of antenna ports, wherein the mapping configuration: maps antenna ports that are co-polarized and with at least a first threshold amount of spatial correlation with respect to one another to different frequency resources of a resource block; and maps antenna ports that are cross-polarized and with less than the first threshold amount of spatial correlation with respect to one another to different time resources of the resource block; and transmitting (215, 1610, 1715) a plurality of channel state information reference signals, CSI-RSs, using the plurality of antenna ports and according to the mapping configuration, wherein mapping the antenna ports comprises: mapping antenna ports with at least the first threshold amount of spatial correlation to resources with less than a second threshold amount of frequency correlation; and mapping antenna ports with less than the first threshold amount of spatial correlation to resources with greater than the second threshold amount of frequency correlation, and wherein the method further comprises either: assigning at least a portion of the antenna ports of the first set or the second set of antenna ports to frequencies separated within a predefined range, the assigning based at least in part on a frequency correlation associated with the at least a portion of the antenna ports, the frequency correlation being less than the second threshold amount; or assigning at least a portion of the antenna ports of the first set or the second set of antenna ports to frequencies separated outside a predefined range, the assigning based at least in part on a frequency correlation associated with the at least a portion of the antenna ports, the frequency correlation being greater than the second threshold amount. maps antenna ports that are co-polarized and with at least a first threshold amount of spatial correlation with respect to one another to different frequency resources of a resource block; and maps antenna ports that are cross-polarized and with less than the first threshold amount of spatial correlation with respect to one another to different time resources of the resource block; and transmitting (215, 1610, 1715) a plurality of channel state information reference signals, CSI-RSs, using the plurality of antenna ports and according to the mapping configuration, wherein mapping the antenna ports comprises: mapping antenna ports with at least the first threshold amount of spatial correlation to resources with less than a second threshold amount of frequency correlation; and mapping antenna ports with less than the first threshold amount of spatial correlation to resources with greater than the second threshold amount of frequency correlation, and wherein the method further comprises either: assigning at least a portion of the antenna ports of the first set or the second set of antenna ports to frequencies separated within a predefined range, the assigning based at least in part on a frequency correlation associated with the at least a portion of the antenna ports, the frequency correlation being less than the second threshold amount; or assigning at least a portion of the antenna ports of the first set or the second set of antenna ports to frequencies separated outside a predefined range, the assigning based at least in part on a frequency correlation associated with the at least a portion of the antenna ports, the frequency correlation being greater than the second threshold amount. mapping antenna ports with at least the first threshold amount of spatial correlation to resources with less than a second threshold amount of frequency correlation; and mapping antenna ports with less than the first threshold amount of spatial correlation to resources with greater than the second threshold amount of frequency correlation, and wherein the method further comprises either: assigning at least a portion of the antenna ports of the first set or the second set of antenna ports to frequencies separated within a predefined range, the assigning based at least in part on a frequency correlation associated with the at least a portion of the antenna ports, the frequency correlation being less than the second threshold amount; or assigning at least a portion of the antenna ports of the first set or the second set of antenna ports to frequencies separated outside a predefined range, the assigning based at least in part on a frequency correlation associated with the at least a portion of the antenna ports, the frequency correlation being greater than the second threshold amount. assigning at least a portion of the antenna ports of the first set or the second set of antenna ports to frequencies separated within a predefined range, the assigning based at least in part on a frequency correlation associated with the at least a portion of the antenna ports, the frequency correlation being less than the second threshold amount; or assigning at least a portion of the antenna ports of the first set or the second set of antenna ports to frequencies separated outside a predefined range, the assigning based at least in part on a frequency correlation associated with the at least a portion of the antenna ports, the frequency correlation being greater than the second threshold amount.