A method and an apparatus are provided for transmitting Channel State Information (CSI) having a reporting mode and being transmitted from a User Equipment (UE) over a PUSCH transmission in an Uplink (UL) cell associated with a Downlink (DL) cell in response to the UE receiving a Downlink Control Information (DCI) format that includes a CSI request field indicating CSI transmission corresponding to one of a plurality of CSI processes associated with measurements of respective reference signals. The method includes obtaining, from the CSI request field, an indication of a CSI process set for a CSI transmission; and transmitting the CSI for the CSI process set indicated by the CSI request field, wherein the CSI request field includes 2 bits of a first CSI process set having a first set of interpretations.