A method performed by a user equipment, UE, the method comprising: receiving, from a base station, configuration information related to a channel state information, CSI, process, the configuration information comprising configuration information of multiple non-zero power, NZP, channel state information reference signal, CSI-RS, resources; receiving, from the base station, at least one parameter configured via higher layer signalling; measuring a channel state based on the configuration information; and reporting, to the base station, a result of measuring the channel state, wherein the CSI process is associated with the multiple NZP CSI-RS resources, wherein the UE determines reference physical downlink shared channel, PDSCH, transmission power corresponding to the multiple NZP CSI-RS resources based on the at least one parameter for measuring the channel state for the CSI process based on the multiple NZP CSI-RS resources, wherein the at least one parameter includes P c which is an assumed ratio of PDSCH energy per resource element, EPRE, to NZP CSI-RS EPRE, and wherein the higher layer signaling comprises the P c of the reference PDSCH transmission power configured for one NZP CSI-RS resource of the multiple NZP CSI-RS resources, and characterised in that the UE determines the Pc for another NZP CSI-RS resource of the multiple NZP CSI-RS resources based on the Pc of the reference PDSCH transmission power configured for the one NZP CSI-RS resource and a number of CSI-RS ports P o of the one NZP CSI-RS resource and a number of CSI-RS ports P k of the another NZP CSI-RS resource according to: P c k = { P c p 0 = 1, p k = 1 p 0 2 ⋅ P c p 0 ≥ 2, p k = 1 2 p k ⋅ P c p 0 = 1, p k ≥ 2 p 0 p k ⋅ P c p 0 ≥ 2, p k ≥ 2,wherein P c (k) is the P c of the k th NZP CSI-RS. receiving, from a base station, configuration information related to a channel state information, CSI, process, the configuration information comprising configuration information of multiple non-zero power, NZP, channel state information reference signal, CSI-RS, resources; receiving, from the base station, at least one parameter configured via higher layer signalling; measuring a channel state based on the configuration information; and reporting, to the base station, a result of measuring the channel state, wherein the CSI process is associated with the multiple NZP CSI-RS resources, wherein the UE determines reference physical downlink shared channel, PDSCH, transmission power corresponding to the multiple NZP CSI-RS resources based on the at least one parameter for measuring the channel state for the CSI process based on the multiple NZP CSI-RS resources, wherein the at least one parameter includes P c which is an assumed ratio of PDSCH energy per resource element, EPRE, to NZP CSI-RS EPRE, and wherein the higher layer signaling comprises the P c of the reference PDSCH transmission power configured for one NZP CSI-RS resource of the multiple NZP CSI-RS resources, and characterised in that the UE determines the Pc for another NZP CSI-RS resource of the multiple NZP CSI-RS resources based on the Pc of the reference PDSCH transmission power configured for the one NZP CSI-RS resource and a number of CSI-RS ports P o of the one NZP CSI-RS resource and a number of CSI-RS ports P k of the another NZP CSI-RS resource according to: P c k = { P c p 0 = 1, p k = 1 p 0 2 ⋅ P c p 0 ≥ 2, p k = 1 2 p k ⋅ P c p 0 = 1, p k ≥ 2 p 0 p k ⋅ P c p 0 ≥ 2, p k ≥ 2,wherein P c (k) is the P c of the k th NZP CSI-RS.