In a Multiple-Input Multiple-Output (MIMO) system including a large number of antenna ports, a base station such as a Node B communicates a total number of antenna ports by communicating the number of antenna ports per Channel State Information Reference Signal (CSI-RS) configuration and one or more CSI-RS configurations. A User Equipment determines the number of antenna ports from the information communicated by the base station by determining the number of CSI-RS configurations sent by the base station and multiplying that number by the number of antenna ports per CSI-RS configuration indicated by the base station.