A method of wireless communication, comprising: receiving information indicating a number of channel state information reference subframes to use in performing CSI measurements in a narrowband communication, wherein the indicated number of CSI reference subframes is equal to four; monitoring subframes on two frequency channels, each of the two frequency channels including a physical downlink control channel, PDCCH; and performing a CSI measurement across the two frequency channels using a number of CSI reference subframes, wherein the performing of the CSI measurement across the two frequency channels comprises: determining a first set of CSI reference subframes on a first frequency channel of the two frequency channels, wherein the first set of CSI reference subframes comprises two CSI reference subframes; determining a second set of CSI reference subframes on a second frequency channel of the two frequency channels, the second set of CSI reference subframes comprises two CSI reference subframes, the first frequency channel being different than the second frequency channel, wherein the first set of CSI reference subframes and the second set of CSI reference subframes comprise together a number of CSI reference subframes equal to four; and performing the CSI measurement across the two frequency channels based on the first set of CSI reference subframes and the second set of CSI reference subframes. monitoring subframes on two frequency channels, each of the two frequency channels including a physical downlink control channel, PDCCH; and performing a CSI measurement across the two frequency channels using a number of CSI reference subframes, wherein the performing of the CSI measurement across the two frequency channels comprises: determining a first set of CSI reference subframes on a first frequency channel of the two frequency channels, wherein the first set of CSI reference subframes comprises two CSI reference subframes; determining a second set of CSI reference subframes on a second frequency channel of the two frequency channels, the second set of CSI reference subframes comprises two CSI reference subframes, the first frequency channel being different than the second frequency channel, wherein the first set of CSI reference subframes and the second set of CSI reference subframes comprise together a number of CSI reference subframes equal to four; and performing the CSI measurement across the two frequency channels based on the first set of CSI reference subframes and the second set of CSI reference subframes. determining a first set of CSI reference subframes on a first frequency channel of the two frequency channels, wherein the first set of CSI reference subframes comprises two CSI reference subframes; determining a second set of CSI reference subframes on a second frequency channel of the two frequency channels, the second set of CSI reference subframes comprises two CSI reference subframes, the first frequency channel being different than the second frequency channel, wherein the first set of CSI reference subframes and the second set of CSI reference subframes comprise together a number of CSI reference subframes equal to four; and performing the CSI measurement across the two frequency channels based on the first set of CSI reference subframes and the second set of CSI reference subframes.